Chapter IX: MISCELLANEOUS.--Technical Education in America.--Branches (3)

Professor Fleeming Jenkin said, "The pressure of the carbons is what favors the transmission of sound."

All the above named scientific men agree that variations of a current passing through a carbon microphone are produced by _pressure_ of the carbons against one another, and they also agree that a jolting motion could not be relied upon to reproduce articulate speech.

Mr. Conrad Cooke said, "The first and most striking principle of Hughes' microphone is a shaking and variable contact between the two parts constituting the microphone." "The shaking and variable contact is produced by the movable portion being effected by sound." "Under Hughes' system, where gas carbon was used, the instruments could not possibly work upon the principle of pressure." "I am satisfied that it is not pressure in the sense of producing a change of resistance." "I do not think pressure has anything to do with it."

Professor Blyth said: "The Hughes microphone depends essentially upon the looseness or delicacy of contact." "I have heard articulate speech with such an instrument without a diaphragm." "There is no doubt that to a certain extent there must be a change in the number of points of surface contact when the pencil is moved." "The action of the Hughes microphone depends more or less upon the looseness or delicacy of the contact and upon the changes in the number of points of surface contact when the pencil is moved."

Mr. Oliver Heaviside, in _The Electrician_ of 10th February last, writes: "There should be no jolting or scraping." "Contacts, though light, should not be loose."

A writer, who signs "W.E.H.," in _The Electrician_ of 24th February last, says: "The variation of current arises from a variation of conductivity between the electrodes, consequent upon the variation of the closeness or pressure of contact;" and also, "there must be a variation of pressure between the electrodes when the transmitter is in action."

It seems, then, that some scientific men agree that variation of pressure is required to produce action in a microphone, and some of them admit that a microphone with loose contacts will transmit articulate speech, while others deny it, and some admit that a jolting or shaking motion of the parts of the microphone does not interfere with articulate speech, while others say such motion would break the circuit, and cannot be relied on.

I will now describe two microphones in which there is a shaking or jolting motion, and loose contacts, and no variation of pressure of the carbons against one another, and both of these microphones when used with an induction coil and battery give most excellent articulation. One of these microphones is made as follows: Two flat plates of carbon are secured to a block of cork, insulated from each other; into a hole of each carbon a pin of carbon fits loosely, projecting above the carbons; another flat piece of carbon, having two holes in it, bridges over the two lower carbons, being kept in its place by the pins of carbon which fit loosely in the holes in it, the bottom carbons being connected with the battery; a block of cork has a flat side of it cut out so as when secured to the lower cork the carbons will not come in contact with it, yet be close enough to it to keep the carbons from falling apart. The cork covering the carbons forms a dome.

Any good telephone receiver when used in connection with this microphone, reproduces articulate speech with remarkable distinctness, especially hissing sounds, and with a loud and full tone.

A description of this microphone was published in _La Lumiere Electrique_, of 15th April, 1882, and a drawing thereof on 29th April of same year.

Another form of microphone is made as follows: Two blocks of gas carbon, C, B, each about one and a half inches long and one inch square, having each a circular hole one and a quarter inches deep and half inch in diameter; these two blocks are embedded in a block of cork, C, about one-quarter of an inch apart, these holes facing each other, each block forming a terminal of the battery and induction coil; a pencil of carbon, C, P, about three-eighths of an inch in diameter, and two inches long, having a ring of ebonite, V, fixed around its center, is placed in the holes of the two fixed blocks; the ebonite ring fitting loosely in between the two blocks so as to prevent the pencil from touching the bottom of the holes in the blocks. The space between the blocks is closed with wax, W, to exclude the air, but not to touch the ring on the pencil. A block of cork fitting close to the carbon blocks on all sides is then firmly secured to the other block of cork. The microphone should lie horizontally or at a slight angle.

This microphone produces in any good telephone perfect articulation in a loud and full tone. In these microphones there is certainly "looseness and delicacy of contact," and there is a "jolting or shaking motion," and it does not seem possible that there can be any "pressure of one carbon against another."

I repeat the question I asked at the beginning of this communication, and hope that it may elicit from you, or some of our scientific men, an explanation of the theory of the action of this form of microphone.

W.C. BARNEY.

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THE DEMBINSKI MICROPHONIC TELEPHONE TRANSMITTER.

This apparatus, which is shown by Figs. 1, 2, and 3, consists of a wooden case, A, of oblong shape, closed by a lid fixed by hinges to the top or one side of the case. The lid is actually a frame for holding a piece of wire gauze, L L, through which the sound waves from the voice can pass. In the case a flat shallow box, E F (or several boxes), is placed, on the lid of which the carbon microphone, D C (Figs. 1 and 3), which is of the ordinary construction, is placed. The box is of thin wood, coated inside with petroleum lamp black, for the purpose of increasing the resonance. It is secured in two lateral slides, fixed to the case. The bottom of the box is pierced with two openings, resembling those in a violin (Fig. 2). Lengthwise across the bottom are stretched a series of brass spiral springs, G G G, which are tuned to a chromatic scale. On the bottom of the case a similar series of springs, not shown, are secured. The apparatus is provided with an induction coil, J, which is connected to the microphone, battery, and telephone receiver (which may be of any known description) in the usual manner.

The inventors claim that the use of the vibrating springs give to the transmitter an increased power over those at present in use. They state that the instrument has given very satisfactory results between Ostende and Arlon, a distance of 314 kilometers (about 200 miles). It does not appear, however, that microphones of the ordinary Gower-Bell type, for example, were tried in competition with the new invention, and in the absence of such tests the mere fact that very satisfactory results were obtained over a length of 200 miles proves very little. With reference to a statement that whistling could be very clearly heard, we may remark that experience has many times proved that the most indifferent form of transmitter will almost always respond well and even powerfully to such forms of vibration.--_Electrical Review_.

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NEW GAS LIGHTERS.

We are going to make known to our readers two new styles of electric lighters whose operation is sure and quick, and the use of which is just as economical as that of those quasi-incombustible little pieces of wood that we have been using for some years under the name of matches.

The first of these is a portable apparatus designed for lighting gas burners, and is based upon the calorific properties of the electric spark produced by the induction bobbin. Its internal arrangement is such as to permit of its being used with a pile of very limited power and dimensions. The apparatus has the form of a rod of a length that may be varied at will, according to the height of the burner to be lighted, and which terminates at its lower part in an ebonite handle about 4 centimeters in width by 20 in length (Fig. 1). This handle is divided into two parts, which are shown isolatedly in Fig. 2, and contains the pile and bobbin. The arrangement of the pile, A, is kept secret, and all that we can say of it is that zinc and chloride of silver are employed as a depolarizer. It is hermetically closed, and carries at one of its extremities a disk, B, and a brass ring, C, attached to its poles and designed to establish a communication between the pile and bobbin when the two parts of the apparatus are screwed together. To this end, two elastic pieces, D and E, fit against B and C and establish a contact. It is asserted that the pile is capable of being used 25,000 times before it is necessary to recharge it. H is an ebonite tube that incloses and protects the induction bobbin, K, whose induced wire communicates on the one hand with the brass tube, L, and on the other with an insulated central conductor, M, which terminates at a point very near the extremity of the brass tube. The currents induced in this wire produce a series of sparks between the tube, L, and the rod, M, which light the gas when the extremity of the apparatus is placed in proximity with the burner.

The ingenious and new part of the system lies in the mode of exciting the induced currents. When the extremity of the tube, L, is brought near the gas burner that is to be lighted, it is only necessary to shove the botton, F, from left to right in order to produce a _limited_ number of sparks sufficient to effect the lighting. The motion of the button has not for effect, as might be believed, the closing of the circuit of the pile upon the inducting circuit of the bobbin. In fact in its normal position, the vibrator is distant from its contact, and the closing of the circuit would produce no action. The motion of F produces a _mechanical_ motion of the spring of the vibrator, which latter acts for a few instants and produces a certain number of contacts that give rise to an equal number of sparks. Owing to this arrangement, the expenditure of electric energy required by each lighting is limited; and, an another hand, the vibrator, which would be incapable of operating if it had to be set in motion by the direct current from the pile, can be actuated _mechanically_. As the motion of the vibrator is derived from the hand of the operator, and not from the pile, it will be comprehended that the latter can, everything being equal, produce a larger number of lightings than an ordinary bobbin and vibrator.

Dr. Naret's _Fiat Lux_ (Fig. 3) is simpler in its operation, and cheaper of application, since it takes its current from the ordinary piles that supply domestic call-bells. It consists essentially of a fine platinum wire supported by a tilting device in connection with the two poles of a pile composed of three Leclanche elements. Upon exerting a vertical pressure on the button placed to the left of the apparatus, either directly or by means of a cord, we at the same time turn the cock and cause the platinum spiral to approach, and the latter then becomes incandescent as a consequence of the closing of the circuit of the pile. After the burner is lighted it is only necessary to leave the apparatus to itself. The cock remains open, the spiral recedes from the burner, the circuit opens anew, and the burner remains lighted until the gas is turned off. This device, then, is particularly appropriate in all cases where there is a pressing need of light, for a single maneuver suffices to open the cock and effect a lighting of the burner.--_La Nature_.

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DISTRIBUTION OF HEAT WHICH IS DEVELOPED BY FORGING.

On the 8th of June. 1874, Tresca presented to the French Academy some considerations respecting the distribution of heat in forging a bar of platinum, and stated the principal reasons which rendered that metal especially suitable for the purpose. He subsequently experimented, in a similar way, with other metals, and finally adopted Senarmont's method for the study of conductibility. A steel or copper bar was carefully polished on its lateral faces, and the polished portion covered with a thin coat of wax. The bar thus prepared was placed under a ram, of known weight, P, which was raised to a height, H, where it was automatically released so as to expend upon the bar the whole quantity of work _T=PH,_ between the two equal faces of the ram and the anvil. A single shock sufficed to melt the wax upon a certain zone and thus to limit, with great sharpness, the part of the lateral faces which had been raised during the shock to the temperature of melting wax. Generally the zone of fusion imitates the area comprised between the two branches of an equilateral hyperbola, but the fall can be so graduated as to restrict this zone, which then takes other forms, somewhat different, but always symmetrical. If A is the area of this zone, b the breadth of the bar, d the density of the metal, c its capacity for heat, and t-t0 the excess of the melting temperature of wax over the surrounding temperature, it is evident that, if we consider A as the base of a horizontal prism which is raised to the temperature t, the calorific effect may be expressed by:

Ab x d x C(t-t0);

and on multiplying this quantity of heat by 425 we find, for the value of its equivalent in work,

T' = 425 AbdC(t-t0).

On comparing T' to T we may consider the experiment as a mechanical operation, having a minimum of:

T'/T = (425/PH)AbdC(t-t0).

After giving diagrams and tables to illustrate the geometrical disposition of the areas of fusion, Tresca feels justified in concluding that the development of heat depends upon the form of the faces and the intensity of the shock; that the points of greatest heat correspond to the points of greatest flow of the metal, and that this flow is really the mechanical phenomenon which gives rise to the calorific phenomenon; that for action sufficiently energetic and for bars of sufficient dimensions, about 0.8 of the labor expended on the blow may be found again in the heat; that the figures formed in the melted wax for shocks of less intensity furnish a kind of diagram of the distribution of the heat and of the deformation in the interior of the bar, but that the calculation of the coefficient of efficiency does not yield satisfactory results in the case of moderate blows.--_Comptes Rendus_.

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TIN IN CANNED FOODS.

[Footnote: Read at an evening meeting of the Pharmaceutical Society, March 5, 1884.]

By PROFESSOR ATTFIELD, F.R.S., ETC.

From time to time, during the past twelve years, paragraphs have appeared in newspapers and other periodicals tending in effect to warn the public at least against the indiscriminate use of canned foods. And whenever there has been any foundation in fact for such cautions, it has commonly rested on the alleged presence and harmfulness of tin in the food. At the worst, the amount of tin present has been absurdly small, affording an opportunity for one literary representative of medicine to state that before a man could be seriously affected by the tin, even if it occurred in the form of a compound of the metal, he would have to consume at a meal ten pounds of the food containing the largest amount of tin ever detected.

But the greatest proportions of tin thus referred to are, according to my experiments, far beyond those ever likely to be actually present in the food itself in the form of a compound of tin; present, that is to say, on account of the action of the fluids or juices of the food on the tin of the can. Such action and such consequent solution of the tin, and consequent admixture of a possibly assimilable compound of tin with the food, in my opinion never occurs to an extent which in relation to health has any significance whatever. The occurrence of tin, not as a compound, but as the metal itself, is, if possible, still less important.

During the last fifteen years I have frequently examined canned foods, not only with respect to the food itself as food, and to the process of canning, but with regard to the relation of the food to, or the influence if any of the metal of, the can itself. So lately as within the past two or three months I have examined sixteen varieties of canned food for metals, with the following results:

Decimal parts of
a grain of tin
(or other foreign
metal) present in
Name of article a quarter of a lb.
examined.

Salmon none.
Lobsters none.
Oysters 0.004
Sardines none.
Lobster paste none.
Salmon paste none.
Bloater paste 0.002
Potted beef none.
Potted tongue none.
Potted "Strasbourg" none.
Potted ham 0.002
Luncheon tongue 0.003
Apricots 0.007
Pears 0.003
Tomatoes 0.007
Peaches 0.004

These proportions of metal are, I say, undeserving of serious notice. I question whether they represent more than the amounts of tin we periodically wear off tin saucepans in preparing food--a month ago I found a trace of tin in water which had been boiled in a tin kettle--or the silver we wear off our forks and spoons. There can be little doubt that we annually pass through our systems a sensible amount of such metals, metallic compounds, and other substances that do not come under the denomination of food; but there is no evidence that they ever did or are ever likely to do harm or occasion us the slightest inconvenience. Harm is far more likely to come to us from noxious gases in the air we breathe than from foreign substances in the food we eat.

But whence come the much less minute amounts of tin--still harmless, be it remembered--which have been stated to be occasionally present in canned foods? They come from the minute particles of metal chipped off from the tin sheets in the operations of cutting, bending, or hammering the parts of the can, or possibly melted off in the operations necessary for the soldering together of the joints of the can. Some may, perhaps, be cut, off by the knife in opening a can. At all events I not unfrequently find such minute particles of metal on carefully washing the external surfaces of a mass of meat just removed from a can, or on otherwise properly treating canned food with the object of detecting such particles. The published processes for the detection of tin in canned food will not reveal more than the amounts stated in the table, or about those amounts; that is to say, a few thousandths or perhaps two or three hundredths of a grain, if this precaution be adopted. If such care be not observed, the less minute amounts may be found. I did not detect any metallic particles in the twelve samples of canned food just mentioned, but during the past few years I have occasionally found small pieces of metal, perhaps amounting in some of the cases to a few tenths of a grain per pound. Now and then small shot-like pieces of tin, or possibly solder, may be met with; but no one has ever found, to my knowledge, such a quantity of actual metallic tin, tinned iron, or solder as, from the point of view of health, can have any significance whatever.

The largest amount of tin I ever detected in actual solution in food was in some canned soup, containing a good deal of lemon juice. It amounted to only three-hundredths of a grain in a half pint of the soup as sent to table. Now, Christison says that quantities of 18 to 44 grains of the very soluble chloride of tin were required to kill dogs in from one to four days. Orfila says that several persons on one occasion dressed their dinner with chloride of tin, mistaking it for salt. One person would thus take not less than 20 to 30 grains of this soluble compound of tin. Yet only a little gastric and bowel disturbance followed, and from this all recovered in a few days. Pereira says that the dose of chloride of tin as an antispasmodic and stimulant is from 1/16 to ½ a grain repeated two or three times daily. Probably no article of canned food, not even the most acid fruit, if in a condition in which it can be eaten, has ever contained, in an ordinary table portion, as much of a soluble salt of tin as would amount to a harmless or useful medicinal dose.

Metallic particles of tin are without any effect on man. A thousand times the quantity ever found in a can of tinned food would do no harm.

Food as acid as say ordinary pickles would dissolve tin. Some manufacturers once proposed using tin stoppers to their bottles of pickles. But the tin was slowly dissolved by the acid of the vinegar. These pickles, however, had a distinctly nasty "metallic" flavor. The idea was abandoned. Probably any article of food containing enough tin to disagree with the system would be too nasty to eat. Purchasers of food may rest assured that the action taken by this firm would be that usually followed. It is not to the interest of manufacturers or other venders to offend the senses of purchasers, still less to do them actual harm, even if no higher motive comes into force.

In the early days of canning, it is just possible that the use of "spirits of salt" in soldering may have resulted in the presence of a little stannous, plumbous, or other chloride in canned food; but such a fault would soon be detected and corrected, and as a matter of fact, resin-soldering is to my knowledge more generally employed--indeed, for anything I know to the contrary, is exclusively employed--in canning food. Any resin that trained access would be perfectly harmless. It is just possible, also, that formerly the tin itself may have contained lead, but I have not found any lead in the sheet tin used for canning of late years.

In conclusion: 1. I have never been able to satisfy myself that a can of ordinary tinned food contains even a useful medicinal dose of such a true soluble _compound_ of tin as is likely to have any effect on man. 2. As for the metal itself, that is the filings or actual metallic particles or fragments, one ounce is a common dose as a vermifuge; harmless even in that quantity to man, and not always so harmful as could be desired to the parasites for whose disestablishment it is administered. One ounce might be contained in about four hundredweight of canned food. 3. If a possibly harmful quantity of a soluble compound, of tin be placed in a portion of canned food, the latter will be so nasty and so unlike any ordinary nasty flavor, so "metallic," in fact, that no sane person will eat it. 4. Respecting the globules of solder (lead and tin) that are occasionally met with in canned food, I believe most persons detect them in the mouth and remove them, as they would shots in game. But if swallowed, they do no harm. Pereira says that metallic lead is probably inert, and that nearly a quarter of a pound has been administered to a dog without any obvious effects. He goes on to say that as it becomes oxidized it occasionally acquires activity, quoting Paulini's statement that colic was produced in a patient who had swallowed a leaden bullet. To allay alarm in the minds of those who fear they might swallow pellets of solder, I may add that Pereira cites Proust for the assurance that an alloy of tin and lead is less easily oxidized than pure lead. 5. Unsoundness in meat does not appear to promote the corrosion or solution of tin. I have kept salmon in cans till it was putrid, testing it occasionally for tin. No trace of tin was detected. Nevertheless, food should not be allowed to remain for a few days, or even hours, in saucepans, metal baking pans, or opened tins or cans, otherwise it _may_ taste metallic. 6. Unsound food, canned or uncanned, may, of course, injure health, and where canned food really has done harm, the harm has in all probability been due to the food and not to the can. 7. What has been termed idiosyncrasy must also be borne in mind. I know a man to whom oatmeal is a poison. Some people cannot eat lobsters, either fresh or tinned. Serious results have followed the eating of not only oatmeal or shell fish, but salmon and mutton; _hydrate_ (misreported _nitrate_) of tin being gratuitously suggested as being contained in the salmon in one case. Possibly there were cases of idiosyncrasy in the eater, possibly the food was unsound, possibly other causes altogether led to the results, but certainly, to my mind, the tin had nothing whatever to do with the matter.

In my opinion, given after well weighing all evidence hitherto forthcoming, the public have not the faintest cause for alarm respecting the occurrence of tin, lead, or any other metal in canned foods.--_Phar. Jour, and Trans., March 8, 1884, p. 719_.

[In reference to Prof. Attfield's statement contained in the closing paragraph, we remark: It is well known that mercury is an ingredient of the solder used in some canning concerns, as it makes an easier melting and flowing solder. In THE SCIENTIFIC AMERICAN for May 27, 1876, in a report of the proceedings of the New York Academy of Science, will be seen the statement of Prof. Falke, who found metallic mercury in a can of preserved corn beef, together with a considerable quantity of albuminate of mercury.--EDS. S.A.]

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VILLA AT DORKING.

The house shown in the illustration was lately erected from the designs of Mr. Charles Bell, F.R.I.B.A. Although sufficiently commodious, the cost has been only about 1,050_l_.--_The Architect_.

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Valerianate of cerium in the vomiting of pregnancy is recommended by Dr. Blondeau in a communication to the _Societe de Therapeutique_. He gives it in doses of 10 centigrammes three times a day.--_Medical Record_.

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TECHNICAL EDUCATION IN AMERICA.

If there is one point more than another in which the exuberant youth and vitality of the American nation is visible it is in that of education, the provision for which is on a most generous scale, carried out with a determination at which the older countries of the Eastern Hemisphere have only arrived by slow degrees and painful experience. Of course the Americans, being young, and having come to the fore, so to speak, full-fledged, have been able to profit by the lessons which they have derived from their neighbors--though it is none the less to their credit that they have profited so well and so quickly. Technical and industrial education has received a more general recognition, and been developed more rapidly, than the general education of the country, partly for the reason that there is no uniform system of the latter throughout the States, but that each individual State and Territory does that which is right in its own eyes. The principal reason, however, is that to possess the knowledge, how to work is the first creed of the American, who considers that the right to obtain that knowledge is the birthright of every citizen, and especially when the manual labor has to be supplemented by a vigorous use of brains. The Americans as a rule do not like heavy or coarse manual labor, thinking it beneath them; and, indeed, when they can get Irish and Chinese to do it for them, perhaps they are not far wrong. But the idea of idleness and loafing is very far from the spirit of the country, and this is why we see the necessity for industrial education so vigorously recognized, both as a national duty, and by private individuals or communities of individuals.

From whatever source it is provided, technical education in the United States comes mainly within the scope of two classes of institutions, viz., agricultural and mechanical colleges; although the two are, as often as not, combined under one establishment, and particularly it forms the subject of a national grant. Indeed, it may be said that the scope of industrial education embraces three classes: the farmer, the mechanic, and the housekeeper; and in the far West we find that provision is made for the education of these three classes in the same schools, it being an accepted idea in the newer States that man and woman (the housekeeper) are coworkers, and are, therefore, entitled to equal and similar educational privileges. On the other hand, in the more conservative East and South, we find that the sexes are educated distinct from each other. In the East, there is generally, also, a separation of subjects. In Massachusetts, for instance, the colleges of agriculture and mechanics are separate affairs, the students being taught in different institutions, viz., the agricultural college and the institute of technology. In Missouri the separation is less defined, the School of Mines and Metallurgy being the, only part that is distinct from the other departments of the University.

One of the chief reasons for the necessity for hastening the extension of technical education in America was the almost entire disappearance of the apprenticeship system, which, in itself, is mainly due to the subdivision of labor so prevalent in the manufacture of everything, from pins to locomotives. The increased use of machinery, the character of which is such as often to put an end to small enterprises, has promoted this subdivision by accumulating workmen in large groups. The beginner, confining himself to one department, is soon able to earn wages, and so he usually continues as he begins. Mr. C.B. Stetson has written on this subject with great force and earnestness, and it will not be amiss to quote a sentence as to the advantages enjoyed by the technically workman. He says that "it is the rude or dexterous workman, rather than the really skilled one, who is supplanted by machinery. Skilled labor requires thinking; but a machine never thinks, never judges, never discriminates. Though its employment does, indeed, enable rude laborers to do many things now which formerly could only be done by dexterous workmen, it is clear that its use has decidedly increased the relative demand for skilled labor as compared with unskilled, and there is abundant room for an additional increase, if it is true, as declared by the most eminent authority, that the power now expended can be readily made to yield three or four times its present results, and ultimately ten or twenty times, when masters and workmen can be had with sufficient intelligence and skill for the direction and manipulation of the tools and machinery that would be invented."

The establishment of colleges and universities by the aid of national grants has depended very much for their character upon the industrial tendencies of the respective States, it being understood that the land grants have principally been given to those of the newer States and Territories which required development, although some of the institutions of the older States on the Atlantic seaboard have also been recipients of the same fund, which in itself only dates from an act of Congress in 1862. In California and Missouri, both States abounding in mineral resources, there are courses in mining and metallurgy provided in the institutions receiving national aid. In the great grain-producing sections of the Mississippi Valley the colleges are principally devoted to agriculture, whereas the characteristic feature of the Iowa and Kansas schools is the prominence given to industries.

We need not devote attention to the aims and arrangements of the agricultural colleges proper, but will pass at once to those which deal with the mechanical arts, dealing first of all with those that are assisted by the national land grant. Taking them alphabetically, we have first the State Agricultural College of Colorado, in the mechanical and drawing department of which shops for bench work in wood and iron and for forging have been recently erected, this institution being one of the newest in America. In the Illinois Industrial University the student of mechanical engineering receives practice in five shops devoted to pattern-making, blacksmithing, moulding and founding, benchwork for iron, and machine tool-work for iron. In the first shop the practice consists of planing, chiseling, turning, and the preparation of patterns for casting. The ordinary blacksmithing operations take place in the second shop, and those of casting in the third. In the fourth there is, first of all, a course of freehand benchwork, and afterward the fitting of parts is undertaken. In the fifth shop all the fundamental operations on iron by machinery are practiced, the actual work being carefully outlined beforehand by drawings. This department of the University consists, in point of fact, of three separate schools, destined to qualify the student for every kind of engineering--mining, railway, mechanical, and architectural. In addition to the shops and machine rooms, there are well furnished cabinets of geological and mineralogical specimens, chemical laboratories for assaying and metallurgy, stamp mill, furnaces, etc., and, in fact, every known vehicle for practical instruction. The school of architecture prepares students for the building profession. Among the subjects in this branch are office work and shop practice, constructing joints in carpentry and joinery, cabinet making and turning, together with modeling in clay. The courses in mathematics, mechanics and physics are the same as those in the engineering school; but the technical studies embrace drawing from casts, wood, stone, brick, and iron construction, turners' work, slating, plastering, painting, and plumbing, architectural drawing and designing, the history and aesthetics of architecture, estimates, agreements specification, heating, lighting, draining, and ventilation. The student's work from scale drawing occupies three terms, carpentry and joinery being taught in the first year, turning and cabinet making in the second, metal and stone work in the third. A more condensed course, known as the builder's course, is given to those who can only stop one year. The machine shop has a steam engine of 16 horse power, two engines and three plain lathes, a planer, a large drill press, a pattern shop, a blacksmith's shop, all of the machinery having been built on the spot. The carpenter's shop is likewise supplied with necessary machine tools, such as saws, planers, tenoning machine, whittlers, etc., the power being furnished by the machine shop. At the date of the last University report, there were 41 students in the courses of mechanical engineering, 41 in those of civil engineering, 3 in mining engineering, and 14 in architecture. Tuition is free in all the University classes, though each student has to pay a matriculation fee of $10, and the incidental expenses amount to about $23 annually. He is charged for material used or apparatus broken, but not for the ordinary wear and tear of instruments. It should be mentioned that the endowment of the Illinois Industrial University is from scrip received from the Government for 480,000 acres of land, of which 454,460 have been sold for $319,178. The real estate of the University, partly made up by donations and partly by appropriations made in successive sessions by the State of Illinois, is estimated at $450,000.

The Purdue University in Indiana, named after its founder, who gave $150,000, which was supplemented by another $50,000 from the State and a bond grant of 390,000 acres, also provides a very complete mechanical course, with shop instruction, divided as follows:

Bench working in wood for 12 weeks, or 120 hours.
Wood-turning " 4 " " 40 "
Pattern-making " 12 " " 120 "
Vise-work in iron " 10 " " 100 "
Forging in iron and steel " 18 " " 180 "
Machine tool-work in iron " 20 " " 200 "

The course in carpentry and joinery embraces: 1. Exercising in sawing and planing to dimensions. 2 Application, or box nailed together. 3 Mortise and tenon joints; a plain mortise and tenon; an open dovetailed mortise and tenon (dovetailed halving); a dovetailed keyed mortise and tenon. 4. Splices. 5. Common dovetailing. 6. Lap dovetailing and rabbeting. 7. Blind or secret dovetail. 8. Miter-box. 9. Carpenter's trestle. 10. Panel door. 11. Roof truss. 12. Section of king-post truss roof. 13. Drawing model.

The course in wood turning includes: 1. Elementary principles: first, straight turning; second, cutting in; third, convex curves with the chisel; fourth, compound curves formed with the gouge. 2. File and chisel handles. 3. Mallets. 4. Picture frames (chuck work). 5. Card receiver (chuck work). 6. Watch safe (chuck work). 7. Ball.

In the pattern-making course the student is supposed to have some skill in bench and lathe work, which will be increased; the direct object being to teach what forms of pattern are in general necessary, and how they must be constructed in order to get a perfect mould from them. The character of the work differs each year. For instance, for the last year, besides simpler patterns easily drawn from the sand, such as glands, ball-cranks, etc., there were a series of flanged pipe-joints for 2½ in. pipes, including the necessary core boxes; also pulley patterns from 6 in. to 10 in. diameter, built in segments for strength, and to prevent warping and shrinkage; and, lastly, a complete set of patterns for a three horse-power horizontal steam engine, all made from drawings of the finished piece. In the vise work in iron, the chief requirements are these: 1, given a block of cast iron 4 in. by 2 in. by 1½ in. in thickness, to reduce the thickness ¼ in. by chipping, and then finishing with the file; 2, to file a round hole square; 3, to file a round hole into elliptical; 4, given a 3 in. cube of wrought iron, to cut a spline 3 in. by 3/8 in. by ¼ in., and second, when the under side is a one half round hollow--these two cuts involve the use of the cope chisel and the round nose chisel, and are examples of very difficult chipping; 5, round tiling or hand-vise work; 6, scraping; 7, special examples of fitting. In the forging classes are elementary processes, driving, bending, and upsetting; courses in welding; miscellaneous forging; steel forging, including hardening and tempering in all its details.

It is worth mentioning that in the industrial art school of the Purdue University there were 13 of the fair sex as students, besides one in the chemical school, and two going through the mechanical courses just detailed, showing that the scope of woman's industry is less limited in America than in England. The Iowa State Agricultural College has also two departments of mechanical and civil engineering, the former including a special course of architecture. The workshop practice, which occupies three forenoons of 2½ hours each per week, is, however, of more general character, and is not pursued with such a regard to any special calling as in the case of the Purdue University.

The Kansas State Agricultural College has a course of carpentry, though designed rather more to meet the everyday necessities of a farmer's life. In fact, all the students are obliged to attend these classes, and take the same first lessons in sawing, planing, lumber dressing, making mortises, tenons, and joints, and in general use of tools--just the kind of instruction that every English lad should have before he is shipped off to the Colonies. This farmer's course in the Kansas College provides for a general training in mechanical handiwork, but facilities are given also to those who wish to follow out the trade, and special instruction is provided in the whole range of work, from framing to stair-building, as also in iron work, such as ordinary forging, filing, tempering, etc. Of the students attending this college, 75 percent, are from farmers' homes, and the majority of the remainder from the families of mechanics and tradesmen.

The State College of Maine provides courses for both civil and mechanical engineers, and has two shops equipped according to the Russian system. Forge and vise work are taught in them, though it is not the object of the college so much to teach the details of any one trade as to qualify students by general knowledge to undertake any of them afterward. A much more complete and thorough technical education is given in the Massachusetts Institute of Technology at Boston, where there are distinct classes for civil, mechanical, mining, geological, and architectural engineering. The following are the particulars of the instruction in the architectural branch, which commences in the student's second year, with Greek, Roman, and Mediæval architectural history, the Orders and their applications, drawing, sketching, and tracing, analytic geometry, differential calculus, physics, descriptive geometry, botany, and physical geography. In the third year the course is extended to the theory of decoration, color, form, and proportion; conventionalism, symbolism, the decorative arts, stained glass, fresco painting, tiles, terra-cotta, original designs, specifications, integral calculus, strength of materials, dynamics, bridges and roofs, stereotomy. In the fourth year the student is turned out a finished architect, after a course of the history of ornament, the theory of architecture, stability of structure, flow of gases, shopwork (carpentry), etc.

The number of students in this very comprehensive Institute of Technology was, by the latest report, 390, of whom 138 were undergoing special courses, 39 were in the schools of mechanical art, and 49 in the Lowell School of Practical Design. Tuition is charged at the rate of 200 dols. for the institute proper, and 150 dols. for the mechanical schools, the average expenses per student being about 254 dols. There are 10 free scholarships, of which two are given for mechanical art. The Lowell School has been established by the trustee of the Lowell Institute to afford free technical education, under the auspices of the Institute of Technology, to both sexes--a large number of young women availing themselves of it in connection with their factory work at Lowell. The courses include practical designs for manufactures, and the art of making patterns for prints, delaines, silks, paperhangings, carpets, oilcloth, etc., and the school is amply provided with pattern looms. Indeed, the whole of the appliances for practical teaching at the Institute are on such a complete scale that at the risk of being a little tedious it is as well to enumerate them. They comprise laboratories devoted to chemistry, mineralogy, metallurgy, and industrial chemistry; there are also microscopic, spectroscopic, and organic laboratories. In other branches there are laboratories and museums of steam engineering, mining, and metallurgy, biology and architecture, together with an observatory, much used in connection with geodesy and practical astronomy. The steam engineering laboratory provides practice in testing, adjusting, and managing steam machinery. The appliances in connection with mining and metallurgy include a five-stamp battery, Blake crusher, automatic machine jigs, an engine pulverizer, a Root and a Sturtevant blower, with blast reverberating, wasting, cupellation, and fusion furnaces, and all other means for reducing ores. The architectural museum contains many thousand casts, models, photographs, and drawings. The shops for handwork are large and well arranged, and include a vise-shop, forge shop, machine, tool, and lathe shops, foundry, rooms for pattern making, weaving, and other industrial institutions. The vise-shop contains four heavy benches, with 32 vises attached, giving a capacity for teaching 128 students the course every ten weeks, or 640 in a year of fifty weeks. The forge-shop has eight forges. The foundry has 16 moulding benches, an oven for core baking, and a blast furnace of one-half ton capacity. The pattern-weaving room is provided with five looms, one of them in 20-harness, and 4-shuttle looms, and another an improved Jacquard pattern loom. It may safely be said that there is nor an establishment in the world better equipped for industrial and technical education than this Institute of Massachusetts.--_London Building News_.

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IVORY GETTING SCARCE.--The stock of ivory in London is estimated at about forty tons in dealers' private warehouses, whereas formerly they usually held about one hundred tons. One fourth of all imported into England goes to the Sheffield cutlers. No really satisfactory substitute for ivory has been found, and millions await the discoverer of one. The existing substitutes will not take the needed polish.

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THE ANAESTHETICS OF JUGGLERS.

Fakirs are religious mendicants who, for the purpose of exciting the charity of the public, assume positions in which it would seem impossible that they could remain, submit themselves to fearful tortures, or else, by their mode of living, their abstinence, and their indifference to inclement weather and to external things, try to make believe that, owing to their sanctity, they are of a species superior to that of common mortals.

In the Indies, these fakirs visit all the great markets, all religious fetes, and usually all kinds of assemblages, in order to exhibit, themselves. If one of them exhibits some new peculiarity, some curious deformity, a strange posture, or, finally, any physiological curiosity whatever that surpasses those of his confreres, he becomes the attraction of the fete, and the crowd surrounds him, and small coin and rupees begin to fall into his bowl.

Fakirs, like all persons who voluntarily torture themselves, are curious examples of the modifications that will, patience, and, so to speak, "art" can introduce into human nature, and into the sensitiveness and functions of the organs. If these latter are capable of being improved, of having their functions developed and of acquiring more strength (as, for example, the muscles of boxers, the breast of foot racers, the voice of singers, etc.), these same organs, on the contrary, can be atrophied or modified, and their functions be changed in nature. It is in such degradation and such degeneration of human nature that fakirs excel, and it is from such a point of view that they are worth studying.

We may, so to speak, class these individuals according to the grades of punishments that they inflict upon themselves, or according to the deformities that they have caused themselves to undergo. But, as we have already said, the number of both of these is extremely varied, each fakir striving in this respect to eclipse his fellows. It is only necessary to open a book of Indian travel to find descriptions of fakirs in abundance; and such descriptions might seem exaggerated or unlikely were they not so concordant. The following are a few examples:

_Immovable fakirs_.--The number of these is large. They remain immovable in the spot they have selected, and that too for an exceedingly long period of time. An example of one of these is cited who remained standing for twelve years, his arms crossed upon his breast, without moving and without lying or sitting down. In such cases charitable persons always take it upon themselves to prevent the fakir from dying of starvation. Some remain sitting, immovable, and apparently lifeless, while others, who lie stretched out upon the ground, look like corpses. It may be easily imagined what a state one of these beings is in after a few months or years of immobility. He is extremely lean, his limbs are atrophied, his body is black with filth and dust, his hair is long and dishevelled, his beard is shaggy, his finger and toe nails have become genuine claws, and his aspect is frightful. This, however, is a character common to all fakirs.

We may likewise class among the immovables those fakirs who cause themselves to be interred up to the neck, and who remain thus with their head sticking out of the ground either during the entire time the fair or fete lasts or for months and years.

_Anchylotic Fakirs_.--The number of fakirs who continue to hold one or both arms outstretched is very large in India. The following description of one of them is given by a traveler: "He was a goussain--a religious mendicant--who had dishevelled hair and beard, and horrible tattooings upon his face, and, what was most hideous, was his left arm, which, withered and anchylosed, stuck up perpendicularly from the shoulder. His closed hand, surrounded by straps, had been traversed by the nails, which, continuing to grow, had bent like claws on the other side. Finally, the hollow of this hand, which was filled with earth, served as a pot for a small sacred myrtle."

Other fakirs hold their two arms above their head, the hands crossed, and remain perpetually in such a position. Others again have one or both arms extended. Some hang by their feet from the limb of a tree by means of a cord, and remain head downward for days at a time, with their face uncongested and their voice clear, counting their beads and mumbling prayers.

One of the most remarkable peculiarities of fakirs is the faculty that certain of them possess of remaining entirely buried in vaults and boxes, and inclosed in bags, etc., for weeks and months, and, although there is a certain deceit as regards the length of their absolute abstinence, it nevertheless seems to be a demonstrated fact that, after undergoing a peculiar treatment, they became plunged into a sort of lethargy that allows them to remain for several days or weeks without taking food. Certain fakirs that have been interred under such conditions have, it appears, passed ten months or a year in their grave.

_Tortured Fakirs_.--Fakirs that submit themselves to tortures are very numerous. Some of them perform exercises analogous to those of the Aissaoua. Mr. Rousselet, in his voyage to the Indies, had an opportunity of seeing some of these at Bhopal, and the following is the picturesque description that he gives of them: "I remarked some groups of religious mendicants of a frightfully sinister character. They were Jogins, who, stark naked and with dishevelled hair, were walking about, shouting, and dancing a sort of weird dance. In the midst of their contortions they brandished long, sharp poniards, of a special form, provided with steel chains. From time to time, one of these hallucinated creatures would drive the poniard into his body (principally into the sides of his chest), into his arms, and into his legs, and would only desist when, in order to calm his apparent fury, the idlers who were surrounding him threw a sufficient number of pennies to him."

At the time of the feast of the Juggernaut one sees, or rather one _did_ see before the English somewhat humanized this ceremony, certain fakirs suspended by their flesh from iron hooks placed along the sides of the god's car. Others had their priests insert under their shoulder blades two hooks, that were afterward fixed to a long pole capable of pivoting upon a post. The fakirs were thus raised about thirty feet above ground, and while being made to spin around very rapidly, smilingly threw flowers to the faithful. Others, again, rolled over mattresses garnished with nails, lance-points, poniards, and sabers, and naturally got up bathed in blood. A large number cause 120 gashes (the sacred number) to be made in their back and breast in honor of their god. Some pierce their tongue with a long and narrow poniard, and remain thus exposed to the admiration of the faithful. Finally, many of them are content to pass points of iron or rods made of reed through folds in their skin. It will be seen from this that fakirs are ingenious in their modes of exciting the compassion and charity of the faithful.

Elsewhere, among a large number of savage tribes and half-civilized peoples, we find aspirants to the priesthood of the fetiches undergoing, under the direction of the members of the religious caste that they desired to enter, ordeals that are extremely painful. Now, it has been remarked for a long time that, among the neophytes, although all are prepared by the same hands, some undergo these ordeals without manifesting any suffering, while others cannot stand the pain, and so run away with fright. It has been concluded from this that the object of such ordeals is to permit the caste to make a selection from among their recruits, and that, too, by means of anesthetics administered to the chosen neophytes.

In France, during the last two centuries, when torturing the accused was in vogue, some individuals were found to be insensible to the most fearful tortures, and some even, who were plunged into a species of somnolence or stupefaction, slept in the hands of the executioner.