Chapter VIII: MISCELLANEOUS.--A Characteristic Mining "Rush."--The (4)

As we go further toward the border, west or north, the influence of the settlement of new land is more distinctly felt. Even in Michigan, where new railroads have opened new regions to settlement, the increase in number of farms has been over 55 per cent. In Wisconsin, though the increase in railroad mileage has been about the same as in Michigan, the reported increase in number of farms has been only 28 per cent., but in Iowa it rises to 60 per cent., and in Minnesota to nearly 100 per cent. In Kansas the number of farms is 138,561, against 38,202 in 1870; in Nebraska 63,387, against 12,301; and in Dakota 17,435, against 1,720. In these regions the process is one of creation of new States rather than a change in the social and industrial condition of the population.

Some Southern States have gained largely, but the increase in these, though very great, is less surprising than the new States of the Northwest. The prevailing tendency of Southern agriculture to large farms and the employment of many hands is especially felt in States where land is still abundant. The greatest increase is in Texas, where 174,184 farms are reported, against 61,125 in 1870; in Florida, with 23,438 farms, against 10,241 in 1870; and in Arkansas, with 94,433 farms, against 49,424 in 1870. In Missouri 215,575 farms are reported, against 148,228 in 1870. In these States, though social changes have been great, the increase in number of farms has been largely due to new settlements, as in the States of the far Northwest. But the change in the older Southern States is of a different character.

Virginia, for example, has long been settled, and had 77,000 farms thirty years ago. But the increase in number within the past ten years has been 44,668, or 60.5 per cent. Contrasting this with the increase in New York, a remarkable difference appears. West Virginia had few more farms ten years ago than New Jersey; now it has nearly twice as many, and has gained in number nearly 60 per cent. North Carolina, too, has increased 78 per cent. in number of farms since 1870, and South Carolina 80 per cent. In Georgia the increase has been still greater--from 69,956 to 138,626, or nearly 100 per cent. In Alabama there are 135,864 farms, against 67,382 in 1870, an increase of over 100 per cent. These proportions, contrasted with those for the older Northern States, reveal a change that is nothing less than an industrial revolution. But the force of this tendency to division of estates has been greatest in the States named. Whereas the ratio of increase in number of farms becomes greater in Northern States as we go from the East toward the Mississippi River, at the South it is much smaller in Kentucky, Tennessee, Mississippi, and Louisiana than in the older States on the Atlantic coast. Thus in Louisiana the increase has been from 28,481 to 48,292 farms, or 70 per cent., and in Mississippi from 68,023 to 101,772 farms, or less than 50 per cent., against 100 in Alabama and Georgia. In Kentucky the increase has been from 118,422 to 166,453 farms, or 40 per cent., and in Tennessee from 118,141 to 165,650 farms, or 40 per cent., against 60 in Virginia and West Virginia, and 78 in North Carolina. Thus, while the tendency to division is far greater than in the Northern States of corresponding age, it is found in full force only in six of the older Southern States, Alabama, West Virginia, and four on the Atlantic coast. In these, the revolution already effected foreshadows and will almost certainly bring about important political changes within a few years. In these six States there 310,795 more farm owners or occupants than there were ten years ago.--_N.Y. Tribune_.

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A FARMER'S LIME KILN.

For information about burning lime we republish the following article furnished by a correspondent of the _Country Gentleman_ several years ago:

I send you a description and sketch of a lime-kiln put up on my premises about five years ago. The dimensions of this kiln are 13 feet square by 25 feet high from foundation, and its capacity 100 bushels in 24 hours. It was constructed of the limestone quarried on the spot. It has round iron rods (shown in sketch) passing through, with iron plates fastened to the ends as clamps to make it more firm; the pair nearest the top should be not less than 2 feet from that point, the others interspersed about 2 feet apart--the greatest strain being near the top. The arch should be 7 feet high by 5½ wide in front, with a gather on the top and sides of about 1 foot, with plank floor; and if this has a little incline it will facilitate shoveling the lime when drawn. The arch should have a strong capstone; also one immediately under the well of the kiln, with a hole 2 feet in diameter to draw the lime through; or two may be used with semicircle cut in each. Iron bars 2 inches wide by 1/8 inch thick are used in this kiln for closing it, working in slots fastened to capstone. These slots must be put in before the caps are laid. When it is desired to draw lime, these bars may be pushed laterally in the slots, or drawn out entirely, according to circumstances; 3 bars will be enough. The slots are made of iron bars 1½ inches wide, with ends rounded and turned up, and inserted in holes drilled through capstone and keyed above.

The well of the kiln is lined with fire-brick one course thick, with a stratum of coal ashes three inches thick tamped in between the brick and wall, which proves a great protection to the wall. About 2,000 fire-bricks were used. The proprietors of this kiln say about one-half the lower part of the well might have been lined with a first quality of common brick and saved some expense and been just as good. The form of the well shown in Fig. 3 is 7 feet in diameter in the bilge, exclusive of the lining of brick and ashes. Experiments in this vicinity have proved this to be the best, this contraction toward the top being absolutely necessary, the expansion of the stone by the heat is so great that the lime cannot be drawn from perpendicular walls, as was demonstrated in one instance near here, where a kiln was built on that principle. The kiln, of course, is for coal, and our stone requires about three-quarters of a ton per 100 bushels of lime, but this, I am told, varies according to quality, some requiring more than others; the quantity can best be determined by experimenting; also the regulation of the heat--if too great it will cause the stones to melt or run together as it were, or, if too little, they will not be properly burned. The business requires skill and judgment to run it successfully.

This kiln is located at the foot of a steep bluff, the top about level with the top of the kiln, with railway track built of wooden sleepers, with light iron bars, running from the bluff to the top of the kiln, and a hand-car makes it very convenient filling the kiln. Such a location should be had if possible. Your inquirer may perhaps get some ideas of the principles of a kiln for using _coal_. The dimensions may be reduced, if desired. If for _wood_, the arch would have to be formed for that, and the height of kiln reduced.

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THE MANUFACTURE OF APPLE JELLY.

[Footnote: From the report of the New York Agricultural Society.]

Within the county of Oswego, New York, Dewitt C. Peck reports there are five apple jelly factories in operation. The failure of the apple crop, for some singular and unexplained reason, does not extend in great degree to the natural or ungrafted fruit. Though not so many as common, even of these apples, there are yet enough to keep these five mills and the numerous cider mills pretty well employed. The largest jelly factory is located near the village of Mexico, and as there are some features in regard to this manufacture peculiar to this establishment which may be new and interesting, we will undertake a brief description. The factory is located on the Salmon Creek, which affords the necessary power. A portion of the main floor, first story, is occupied as a saw mill, the slabs furnishing fuel for the boiler furnace connected with the evaporating department. Just above the mill, along the bank of the pond, and with one end projecting over the water, are arranged eight large bins, holding from five hundred to one thousand bushels each, into which the apples are delivered from the teams. The floor in each of these has a sharp pitch or inclination toward the water and at the lower end is a grate through which the fruit is discharged, when wanted, into a trough half submerged in the pond.

The preparation of the fruit and extraction of the juice proceeds as follows: Upon hoisting a gate in the lower end of this trough, considerable current is caused, and the water carries the fruit a distance of from thirty to one hundred feet, and passes into the basement of the mill, where, tumbling down a four-foot perpendicular fall, into a tank, tight in its lower half and slatted so as to permit the escape of water and impurities in the upper half, the apples are thoroughly cleansed from all earthy or extraneous matter. Such is the friction caused by the concussion of the fall, the rolling and rubbing of the apples together, and the pouring of the water, that decayed sections of the fruit are ground off and the rotten pulp passes away with other impurities. From this tank the apples are hoisted upon an endless chain elevator, with buckets in the form of a rake-head with iron teeth, permitting drainage and escape of water, to an upper story of the mill, whence by gravity they descend to the grater. The press is wholly of iron, all its motions, even to the turning of the screws, being actuated by the water power. The cheese is built up with layers inclosed in strong cotton cloth, which displaces the straw used in olden time, and serves also to strain the cider. As it is expressed from the press tank, the cider passes to a storage tank, and thence to the defecator.

This defecator is a copper pan, eleven feet long and about three feet wide. At each end of this pan is placed a copper tube three inches in diameter and closed at both ends. Lying between and connecting these two, are twelve tubes, also of copper, 1½ inches in diameter, penetrating the larger tubes at equal distances from their upper and under surfaces, the smaller being parallel with each other, and 1½ inches apart. When placed in position, the larger tubes, which act as manifolds, supplying the smaller with steam, rest upon the bottom of the pan, and thus the smaller pipes have a space of three-fourths of an inch underneath their outer surfaces.

The cider comes from the storage tank in a continuous stream about three-eighths of an inch in diameter. Steam is introduced to the large or manifold tubes, and from them distributed through the smaller ones at a pressure of from twenty-five to thirty pounds per inch. Trap valves are provided for the escape of water formed by condensation within the pipes. The primary object of the defecator is to remove all impurities and perfectly clarify the liquid passing through it. All portions of pomace and other minute particles of foreign matter, when heated, expand and float in the form of scum upon the surface of the cider. An ingeniously contrived floating rake drags off this scum and delivers it over the side of the pan. To facilitate this removal, one side of the pan, commencing at a point just below the surface of the cider, is curved gently outward and upward, terminating in a slightly inclined plane, over the edge of which the scum is pushed by the rake into a trough and carried away. A secondary purpose served by the defecator is that of reducing the cider by evaporation to a partial sirup of the specific gravity of about 20° Baume. When of this consistency the liquid is drawn from the bottom and less agitated portion of the defecator by a siphon, and thence carried to the evaporator, which is located upon the same framework and just below the defecator.

The evaporator consists of a separate system of six copper tubes, each twelve feet long and three inches in diameter. These are each jacketed or inclosed in an iron pipe of four inches internal diameter, fitted with steam-tight collars so as to leave half an inch steam space surrounding the copper tubes. The latter are open at both ends permitting the admission and egress of the sirup and the escape of the steam caused by evaporation therefrom, and are arranged upon the frame so as to have a very slight inclination downward in the direction of the current, and each nearly underneath its predecessor in regular succession. Each is connected by an iron supply pipe, having a steam gauge or indicator attached, with a large manifold, and that by other pipes with a steam boiler of thirty horse power capacity. Steam being let on at from twenty five to thirty pounds pressure, the stream of sirup is received from the defecator through a strainer, which removes any impurities possibly remaining into the upper evaporator tube; passing in a gentle flow through that, it is delivered into a funnel connected with the next tube below, and so, back and forth, through the whole system. The sirup enters the evaporator at a consistency of from 20° to 23° Baume, and emerges from the last tube some three minutes later at a consistency of from 30° to 32° Baume, which is found on cooling to be the proper point for perfect jelly. This point is found to vary one or two degrees, according to the fermentation consequent upon bruises in handling the fruit, decay of the same, or any little delay in expressing the juice from the cheese. The least fermentation occasions the necessity for a lower reduction. To guard against this, no cheese is allowed to stand over night, no pomace left in the grater or vat, no cider in the tank; and further to provide against fermentation, a large water tank is located upon the roof and filled by a force pump, and by means of hose connected with this, each grater, press, vat, tank, pipe, trough, or other article of machinery used, can be thoroughly washed and cleansed. Hot water, instead of cider, is sometimes sent through the defecator, evaporator, etc., until all are thoroughly scalded and purified. If the saccharometer shows too great or too little reduction, the matter is easily regulated by varying the steam pressure in the evaporator by means of a valve in the supply pipe. If boiled cider instead of jelly is wanted for making pies, sauces, etc., it is drawn off from one of the upper evaporator tubes according to the consistency desired; or can be produced at the end of the process by simply reducing the steam pressure.

As the jelly emerges from the evaporator it is transferred to a tub holding some fifty gallons, and by mixing a little therein, any little variations in reduction or in the sweetness or sourness of the fruit used are equalized. From this it is drawn through faucets, while hot, into the various packages in which it is shipped to market. A favorite form of package for family use is a nicely turned little wooden bucket with cover and bail, two sizes, holding five and ten pounds respectively. The smaller packages are shipped in cases for convenience in handling. The present product of this manufactory is from 1,500 to 1,800 pounds of jelly each day of ten hours. It is calculated that improvements now in progress will increase this to something more than a ton per day. Each bushel of fruit will produce from four to five pounds of jelly, fruit ripening late in the season being more productive than earlier varieties. Crab apples produce the finest jelly; sour, crabbed, natural fruit makes the best looking article, and a mixture of all varieties gives most satisfactory results as to flavor and general quality.

As the pomace is shoveled from the finished cheese, it is again ground under a toothed cylinder, and thence drops into large troughs, through a succession of which a considerable stream of water is flowing. Here it is occasionally agitated by raking from the lower to the upper end of the trough as the current carries it downward, and the apple seeds becoming disengaged drop to the bottom into still water, while the pulp floats away upon the stream. A succession of troughs serves to remove nearly all the seeds. The value of the apple seeds thus saved is sufficient to pay the daily wages of all the hands employed in the whole establishment. The apples are measured in the wagon box, one and a half cubic feet being accounted a bushel.

This mill ordinarily employs about six men: One general superintendent, who buys and measures the apples, keeps time books, attends to all the accounts and the working details of the mill, and acts as cashier; one sawyer, who manufactures lumber for the local market and saws the slabs into short lengths suitable for the furnace; one cider maker, who grinds the apples and attends the presses; one jelly maker, who attends the defecator, evaporator, and mixing tub, besides acting as his own fireman and engineer; one who attends the apple seed troughs and acts as general helper, and one man-of-all-work to pack, ship and assist whenever needed. The establishment was erected late in the season of 1880, and manufactured that year about forty-five tons of jelly, besides considerable cider exchanged to the farmers for apples, and some boiled cider.

The price paid for apples in 1880, when the crop was superabundant, was six to eight cents per bushel; in 1881, fifteen cents. The proprietor hopes next year to consume 100,000 bushels. These institutions are important to the farmer in that they use much fruit not otherwise valuable and very perishable. Fruit so crabbed and gnarled as to have no market value, and even frozen apples, if delivered while yet solid, can be used. (Such apples are placed in the water while frozen, the water draws the frost sufficiently to be grated, and passing through the press and evaporator before there is time for chemical change, they are found to make very good jelly. They are valuable to the consumer by converting the perishable, cheap, almost worthless crop of the bearing and abundant years into such enduring form that its consumption may be carried over to years of scarcity and furnish healthful food in cheap and pleasant form to many who would otherwise be deprived; and lastly, they are of great interest to society, in that they give to cider twice the value for purposes of food that it has or can have, even to the manufacturer, for use as a beverage and intoxicant.

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IMPROVED GRAPE BAGS.

It stands to reason that were our summers warmer we should be able to grow grapes successfully on open walls; it is therefore probable that a new grape bag, the invention of M. Pelletier, 20 Rue de la Banque, Paris, intended to serve a double purpose, viz., protecting the fruit and hastening its maturity, will, when it becomes known, be welcomed in this country. It consists of a square of curved glass so fixed to the bag that the sun's rays are concentrated upon the fruit, thereby rendering its ripening more certain in addition to improving its quality generally. The glass is affixed to the bag by means of a light iron wire support. It covers that portion of it next the sun, so that it increases the amount of light and warms the grapes without scorching them, a result due to the convexity of the glass and the layer of air between it and the bag. M. Pelletier had the idea of rendering these bags cheaper by employing plain squares instead of curved ones, but the advantage thus obtained was more than counterbalanced by their comparative inefficacy. In practice it was found that the curved squares gave an average of 7° more than the straight ones, while there was a difference of 10° when the bags alone were used, thus plainly demonstrating the practical value of the invention.

Whether these glass-fronted bags would have much value in the case of grapes grown under glass in the ordinary way is a question that can only be determined by actual experiment; but where the vines are on walls, either under glass screens or in the open air, so that the bunches feel the full force of the sun's rays, there can be no doubt as to their utility, and it is probable that by their aid many of the continental varieties which we do not now attempt to grow in the open, and which are scarcely worthy of a place under glass, might be well ripened. At any rate we ought to give anything a fair trial which may serve to neutralize, if only in a slight degree, the uncertainty of our summers. As it is, we have only about two varieties of grapes, and these not the best of the hardy kinds, as regards flavor and appearance, that ripen out of doors, and even these do not always succeed. We know next to nothing of the many really well-flavored kinds which are so much appreciated in many parts of the Continent. The fact is, our outdoor culture of grapes offers a striking contrast to that practiced under glass, and although our comparatively sunless and moist climate affords some excuse for our shortcomings in this respect, there is no valid reason for the utter want of good culture which is to be observed in a general way.

Given intelligent training, constant care in stopping the laterals, and checking mildew as well as thinning the berries, allowing each bunch to get the full benefit of sun and air, and I believe good eatable grapes would often be obtained even in summers marked by a low average temperature.

If, moreover, to a good system of culture we add some such mechanical contrivance as that under notice whereby the bunches enjoy an average warmth some 10° higher than they otherwise would do, we not only insure the grapes coming to perfection in favored districts, but outdoor culture might probably be practiced in higher latitudes than is now practicable.

The improved grape bag would also offer great facilities for destroying mildew or guarantee the grapes against its attacks, as a light dusting administered as soon as the berries were fairly formed would suffice for the season, as owing to the glass protecting the berries from driving rains, which often accompany south or south-west winds in summer and autumn, the sulphur would not be washed off.

The inventor claims, and we should say with just reason, that these glass fronted bags would be found equally serviceable for the ripening of pears and other choice fruits, and with a view to their being employed for such a purpose, he has had them made of varying sizes and shapes. In conclusion, it may be observed that, in addition to advancing the maturity of the fruits to which they are applied, they also serve to preserve them from falling to the ground when ripe.--J. COBNHILL, _in the Garden_.

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UTILIZATION OF SOLAR HEAT.

At a popular fête in the Tuileries Gardens I was struck with an experiment which seems deserving of the immediate attention of the English public and military authorities.

Among the attractions of the fête was an apparatus for the concentration and utilization of solar heat, and, though the sun was not very brilliant, I saw this apparatus set in motion a printing machine which printed several thousand copies of a specimen newspaper entitled the _Soleil Journal_.

The sun's rays are concentrated in a reflector, which moves at the same rate as the sun and heats a vertical boiler, setting the motive steam-engine at work. As may be supposed, the only object was to demonstrate the possibility of utilizing the concentrated heat of the solar rays; but I closely examined it, because the apparatus seems capable of great utility in existing circumstances. Here in France, indeed, there is a radical drawback--the sun is often overclouded.

Thousands of years ago the idea of utilizing the solar rays must have suggested itself, and there are still savage tribes who know no other mode of combustion; but the scientific application has hitherto been lacking. This void this apparatus will fill up. About fifteen years ago Professor Mouchon, of Tours, began constructing such an apparatus, and his experiments have been continued by M. Pifre, who has devoted much labor and expense to realizing M. Mouchou's idea. A company has now come to his aid, and has constructed a number of apparatus of different sizes at a factory which might speedily turn out a large number of them. It is evident that in a country of uninterrupted sunshine the boiler might be heated in thirty or forty minutes. A portable apparatus could boil two and one-half quarts an hour, or, say, four gallons a day, thus supplying by distillation or ebullition six or eight men. The apparatus can be easily carried on a man's back, and on condition of water, even of the worst quality, being obtainable, good drinking and cooking water is insured. M. De Rougaumond, a young scientific writer, has just published an interesting volume on the invention. I was able yesterday to verify his statements, for I saw cider made, a pump set in motion, and coffee made--in short, the calorific action of the sun superseding that of fuel. The apparatus, no doubt, has not yet reached perfection, but as it is it would enable the soldier in India or Egypt to procure in the field good water and to cook his food rapidly. The invention is of especial importance to England just now, but even when the Egyptian question is settled the Indian troops might find it of inestimable value.

Red tape should for once be disregarded, and a competent commission forthwith sent to 30 Rue d'Assas, with instructions to report immediately, for every minute saved may avoid suffering for Englishmen fighting abroad for their country. I may, of course, be mistaken, but a commission would decide, and if the apparatus is good the slightest delay in its adoption would be deplorable.--_Paris Correspondence London Times_.

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HOW TO ESTABLISH A TRUE MERIDIAN.

[Footnote: A paper read before the Engineers' Club of Philadelphia.]

By PROFESSOR L. M. HAUPT.

INTRODUCTORY.

The discovery of the magnetic needle was a boon to mankind, and has been of inestimable service in guiding the mariner through trackless waters, and the explorer over desert wastes. In these, its legitimate uses, the needle has not a rival, but all efforts to apply it to the accurate determination of permanent boundary lines have proven very unsatisfactory, and have given rise to much litigation, acerbity, and even death.

For these and other cogent reasons, strenuous efforts are being made to dispense, so far as practicable, with the use of the magnetic needle in surveying, and to substitute therefor the more accurate method of traversing from a true meridian. This method, however, involves a greater degree of preparation and higher qualifications than are generally possessed, and unless the matter can be so simplified as to be readily understood, it is unreasonable to expect its general application in practice.

Much has been written upon the various methods of determining, the true meridian, but it is so intimately related to the determination of latitude and time, and these latter in turn upon the fixing of a true meridian, that the novice can find neither beginning nor end. When to these difficulties are added the corrections for parallax, refraction, instrumental errors, personal equation, and the determination of the probable error, he is hopelessly confused, and when he learns that time may be sidereal, mean solar, local, Greenwich, or Washington, and he is referred to an ephemeris and table of logarithms for data, he becomes lost in "confusion worse confounded," and gives up in despair, settling down to the conviction that the simple method of compass surveying is the best after all, even if not the most accurate.

Having received numerous requests for information upon the subject, I have thought it expedient to endeavor to prepare a description of the method of determining the true meridian which should be sufficiently clear and practical to be generally understood by those desiring to make use of such information.

This will involve an elementary treatment of the subject, beginning with the

DEFINITIONS.

The _celestial sphere_ is that imaginary surface upon which all celestial objects are projected. Its radius is infinite.

The _earth's axis_ is the imaginary line about which it revolves.

The _poles_ are the points in which the axis pierces the surface of the earth, or of the celestial sphere.

A _meridian_ is a great circle of the earth cut out by a plane passing through the axis. All meridians are therefore north and south lines passing through the poles.

From these definitions it follows that if there were a star exactly at the pole it would only be necessary to set up an instrument and take a bearing to it for the meridian. Such not being the case, however, we are obliged to take some one of the near circumpolar stars as our object, and correct the observation according to its angular distance from the meridian at the time of observation.

For convenience, the bright star known as Ursæ Minoris or Polaris, is generally selected. This star apparently revolves about the north pole, in an orbit whose mean radius is 1° 19' 13",[1] making the revolution in 23 hours 56 minutes.

[Footnote 1: This is the codeclination as given in the Nautical Almanac. The mean value decreases by about 20 seconds each year.]

During this time it must therefore cross the meridian twice, once above the pole and once below; the former is called the _upper_, and the latter the _lower meridian transit or culmination_. It must also pass through the points farthest east and west from the meridian. The former is called the _eastern elongation_, the latter the _western_.

An observation may he made upon Polaris at any of these four points, or at any other point of its orbit, but this latter case becomes too complicated for ordinary practice, and is therefore not considered.

If the observation were made upon the star at the time of its upper or lower culmination, it would give the true meridian at once, but this involves a knowledge of the true local time of transit, or the longitude of the place of observation, which is generally an unknown quantity; and moreover, as the star is then moving east or west, or at right angles to the place of the meridian, at the rate of 15° of arc in about one hour, an error of so slight a quantity as only four seconds of time would introduce an error of one minute of arc. If the observation be made, however, upon either elongation, when the star is moving up or down, that is, in the direction of the vertical wire of the instrument, the error of observation in the angle between it and the pole will be inappreciable. This is, therefore, the best position upon which to make the observation, as the precise time of the elongation need not be given. It can be determined with sufficient accuracy by a glance at the relative positions of the star Alioth, in the handle of the Dipper, and Polaris (see Fig. 1). When the line joining these two stars is horizontal or nearly so, and Alioth is to the _west_ of Polaris, the latter is at its _eastern_ elongation, and _vice versa_, thus:

But since the star at either elongation is off the meridian, it will be necessary to determine the angle at the place of observation to be turned off on the instrument to bring it into the meridian. This angle, called the azimuth of the pole star, varies with the latitude of the observer, as will appear from Fig 2, and hence its value must be computed for different latitudes, and the surveyor must know his _latitude_ before he can apply it. Let N be the north pole of the celestial sphere; S, the position of Polaris at its eastern elongation; then N S=1° 19' 13", a constant quantity. The azimuth of Polaris at the latitude 40° north is represented by the angle N O S, and that at 60° north, by the angle N O' S, which is greater, being an exterior angle of the triangle, O S O. From this we see that the azimuth varies at the latitude.

We have first, then, to _find the latitude of the place of observation_.

Of the several methods for doing this, we shall select the simplest, preceding it by a few definitions.

A _normal_ line is the one joining the point directly overhead, called the _zenith_, with the one under foot called the _nadir_.

The _celestial horizon_ is the intersection of the celestial sphere by a plane passing through the center of the earth and perpendicular to the normal.

A _vertical circle_ is one whose plane is perpendicular to the horizon, hence all such circles must pass through the normal and have the zenith and nadir points for their poles. The _altitude_ of a celestial object is its distance above the horizon measured on the arc of a vertical circle. As the distance from the horizon to the zenith is 90°, the difference, or _complement_ of the altitude, is called the _zenith distance_, or _co-altitude_.

The _azimuth_ of an object is the angle between the vertical plane through the object and the plane of the meridian, measured on the horizon, and usually read from the south point, as 0°, through west, at 90, north 180°, etc., closing on south at 0° or 360°.

These two co-ordinates, the altitude and azimuth, will determine the position of any object with reference to the observer's place. The latter's position is usually given by his latitude and longitude referred to the equator and some standard meridian as co-ordinates.

The _latitude_ being the angular distance north or south of the equator, and the _longitude_ east or west of the assumed meridian.

We are now prepared to prove that _the altitude of the pole is equal to the latitude of the place of observation_.

Let H P Z Q¹, etc., Fig. 2, represent a meridian section of the sphere, in which P is the north pole and Z the place of observation, then H H¹ will be the horizon, Q Q¹ the equator, H P will be the altitude of P, and Q¹ Z the latitude of Z. These two arcs are equal, for H C Z = P C Q¹ = 90°, and if from these equal quadrants the common angle P C Z be subtracted, the remainders H C P and Z C Q¹, will be equal.

To _determine the altitude of the pole_, or, in other words, _the latitude of the place_.

Observe the altitude of the pole star _when on the meridian_, either above or below the pole, and from this observed altitude corrected for refraction, subtract the distance of the star from the pole, or its _polar distance_, if it was an upper transit, or add it if a lower. The result will be the required latitude with sufficient accuracy for ordinary purposes.

The time of the star's being on the meridian can be determined with sufficient accuracy by a mere inspection of the heavens. The refraction is _always negative_, and may be taken from the table appended by looking up the amount set opposite the observed altitude. Thus, if the observer's altitude should be 40° 39' the nearest refraction 01' 07", should be subtracted from 40° 37' 00", leaving 40° 37' 53" for the latitude.

TO FIND THE AZIMUTH OF POLARIS.

As we have shown the azimuth of Polaris to be a function of the latitude, and as the latitude is now known, we may proceed to find the required azimuth. For this purpose we have a right-angled spherical triangle, Z S P, Fig. 4, in which Z is the place of observation, P the north pole, and S is Polaris. In this triangle we have given the polar distance, P S = 10° 19' 13"; the angle at S = 90°; and the distance Z P, being the complement of the latitude as found above, or 90°--L. Substituting these in the formula for the azimuth, we will have sin. Z = sin. P S / sin P Z or sin. of Polar distance / sin. of co-latitude, from which, by assuming different values for the co-latitude, we compute the following table:

AZIMUTH TABLE FOR POINTS BETWEEN 26° and 50° N. LAT.

LATTITUDES ___________________________________________________________________ | | | | | | | | | Year | 26° | 28° | 30° | 32° | 34° | 36° | |______|_________|__________|_________|_________|_________|_________| | | | | | | | | | | ° ' " | ° ' " | ° ' " | ° ' " | ° ' " | ° ' " | | 1882 | 1 28 05 | 1 29 40 | 1 31 25 | 1 33 22 | 1 35 30 | 1 37 52 | | 1883 | 1 27 45 | 1 29 20 | 1 31 04 | 1 33 00 | 1 35 08 | 1 37 30 | | 1884 | 1 27 23 | 1 28 57 | 1 30 41 | 1 32 37 | 1 34 45 | 1 37 05 | | 1885 | 1 27 01 | 1 28 35½ | 1 30 19 | 1 32 14 | 1 34 22 | 1 36 41 | | 1886 | 1 26 39 | 1 28 13 | 1 29 56 | 1 31 51 | 1 33 57 | 1 36 17 | |______|_________|__________|_________|_________|_________|_________| | | | | | | | | | Year | 38° | 40° | 42° | 44° | 46° | 48° | |______|_________|__________|_________|_________|_________|_________| | | | | | | | | | | ° ' " | ° ' " | ° ' " | ° ' " | ° ' " | ° ' " | | 1882 | 1 40 29 | 1 43 21 | 1 46 33 | 1 50 05 | 1 53 59 | 1 58 20 | | 1883 | 1 40 07 | 1 42 58 | 1 46 08 | 1 49 39 | 1 53 34 | 1 57 53 | | 1884 | 1 39 40 | 1 42 31 | 1 45 41 | 1 49 11 | 1 53 05 | 1 57 23 | | 1885 | 1 39 16 | 1 42 07 | 1 45 16 | 1 48 45 | 1 52 37 | 1 56 54 | | 1886 | 1 38 51 | 1 41 41 | 1 44 49 | 1 48 17 | 1 52 09 | 1 56 24 | |______|_________|__________|_________|_________|_________|_________| | | | | Year | 50° | |______|_________| | | | | | ° ' " | | 1882 | 2 03 11 | | 1883 | 2 02 42 | | 1884 | 2 02 11 | | 1885 | 2 01 42 | | 1886 | 2 01 11 | |______|_________|

An analysis of this table shows that the azimuth this year (1882) increases with the latitude from 1° 28' 05" at 26° north, to 2° 3' 11" at 50° north, or 35' 06". It also shows that the azimuth of Polaris at any one point of observation decreases slightly from year to year. This is due to the increase in declination, or decrease in the star's polar distance. At 26° north latitude, this annual decrease in the azimuth is about 22", while at 50° north, it is about 30". As the variation in azimuth for each degree of latitude is small, the table is only computed for the even numbered degrees; the intermediate values being readily obtained by interpolation. We see also that an error of a few minutes of latitude will not affect the result in finding the meridian, e.g., the azimuth at 40° north latitude is 1° 43' 21", that at 41° would be 1° 44' 56", the difference (01' 35") being the correction for one degree of latitude between 40° and 41°. Or, in other words, an error of one degree in finding one's latitude would only introduce an error in the azimuth of one and a half minutes. With ordinary care the probable error of the latitude as determined from the method already described need not exceed a few minutes, making the error in azimuth as laid off on the arc of an ordinary transit graduated to single minutes, practically zero.

REFRACTION TABLE FOR ANY ALTITUDE WITHIN THE LATITUDE OF THE UNITED STATES.

_____________________________________________________ | | | | | | Apparent | Refraction | Apparent | Refraction | | Altitude. | _minus_. | Altitude. | _minus_. | |___________|______________|___________|______________| | | | | | | 25° | 0° 2' 4.2" | 38° | 0° 1' 14.4" | | 26 | 1 58.8 | 39 | 1 11.8 | | 27 | 1 53.8 | 40 | 1 9.3 | | 28 | 1 49.1 | 41 | 1 6.9 | | 29 | 1 44.7 | 42 | 1 4.6 | | 30 | 1 40.5 | 43 | 1 2.4 | | 31 | 1 36.6 | 44 | 0 0.3 | | 32 | 1 33.0 | 45 | 0 58.1 | | 33 | 1 29.5 | 46 | 0 56.1 | | 34 | 1 26.1 | 47 | 0 54.2 | | 35 | 1 23.0 | 48 | 0 52.3 | | 36 | 1 20.0 | 49 | 0 50.5 | | 37 | 1 17.1 | 50 | 0 48.8 | |___________|______________|___________|______________|

APPLICATIONS.

In practice to find the true meridian, two observations must be made at intervals of six hours, or they may be made upon different nights. The first is for latitude, the second for azimuth at elongation.

To make either, the surveyor should provide himself with a good transit with vertical arc, a bull's eye, or hand lantern, plumb bobs, stakes, etc.[1] Having "set up" over the point through which it is proposed to establish the meridian, at a time when the line joining Polaris and Alioth is nearly vertical, level the telescope by means of the attached level, which should be in adjustment, set the vernier of the vertical arc at zero, and take the reading. If the pole star is about making its _upper_ transit, it will rise gradually until reaching the meridian as it moves westward, and then as gradually descend. When near the highest part of its orbit point the telescope at the star, having an assistant to hold the "bull's eye" so as to reflect enough light down the tube from the object end to illumine the cross wires but not to obscure the star, or better, use a perforated silvered reflector, clamp the tube in this position, and as the star continues to rise keep the _horizontal_ wire upon it by means of the tangent screw until it "rides" along this wire and finally begins to fall below it. Take the reading of the vertical arc and the result will be the observed altitude.

[Footnote 1: A sextant and artificial horizon may be used to find the _altitude_ of a star. In this case the observed angle must be divided by 2.]

ANOTHER METHOD.

It is a little more accurate to find the altitude by taking the complement of the observed zenith distance, if the vertical arc has sufficient range. This is done by pointing first to Polaris when at its highest (or lowest) point, reading the vertical arc, turning the horizontal limb half way around, and the telescope over to get another reading on the star, when the difference of the two readings will be the _double_ zenith distance, and _half_ of this subtracted from 90° will be the required altitude. The less the time intervening between these two pointings, the more accurate the result will be.

Having now found the altitude, correct it for refraction by subtracting from it the amount opposite the observed altitude, as given in the refraction table, and the result will be the latitude. The observer must now wait about six hours until the star is at its western elongation, or may postpone further operations for some subsequent night. In the meantime he will take from the azimuth table the amount given for his date and latitude, now determined, and if his observation is to be made on the western elongation, he may turn it off on his instrument, so that when moved to zero, _after_ the observation, the telescope will be brought into the meridian or turned to the right, and a stake set by means of a lantern or plummet lamp.

It is, of course, unnecessary to make this correction at the time of observation, for the angle between any terrestrial object and the star may be read and the correction for the azimuth of the star applied at the surveyor's convenience. It is always well to check the accuracy of the work by an observation upon the other elongation before putting in permanent meridian marks, and care should be taken that they are not placed near any local attractions. The meridian having been established, the magnetic variation or declination may readily be found by setting an instrument on the meridian and noting its bearing as given by the needle. If, for example, it should be north 5° _east_, the variation is west, because the north end of the needle is _west_ of the meridian, and _vice versa_.

_Local time_ may also be readily found by observing the instant when the sun's center[1] crosses the line, and correcting it for the equation of time as given above--the result is the true or mean solar time. This, compared with the clock, will show the error of the latter, and by taking the difference between the local lime of this and any other place, the difference of longitude is determined in hours, which can readily be reduced to degrees by multiplying by fifteen, as 1 h. = 15°.

[Footnote 1: To obtain this time by observation, note the instant of first contact of the sun's limb, and also of last contact of same, and take the mean.]

APPROXIMATE EQUATION OF TIME.

_______________________
| | |
| Date. | Minutes. |
|__________|____________|
| | |
| Jan. 1 | 4 |
| 3 | 5 |
| 5 | 6 |
| 7 | 7 |
| 9 | 8 |
| 12 | 9 |
| 15 | 10 |
| 18 | 11 |
| 21 | 12 |
| 25 | 13 |
| 31 | 14 |
| Feb. 10 | 15 |
| 21 | 14 | Clock
| 27 | 13 | faster
| M'ch 4 | 12 | than
| 8 | 11 | sun.
| 12 | 10 |
| 15 | 9 |
| 19 | 8 |
| 22 | 7 |
| 25 | 6 |
| 28 | 5 |
| April 1 | 4 |
| 4 | 3 |
| 7 | 2 |
| 11 | 1 |
| 15 | 0 |
| |------------|
| 19 | 1 |
| 24 | 2 |
| 30 | 3 |
| May 13 | 4 | Clock
| 29 | 3 | slower.
| June 5 | 2 |
| 10 | 1 |
| 15 | 0 |
| |------------|
| 20 | 1 |
| 25 | 2 |
| 29 | 3 |
| July 5 | 4 |
| 11 | 5 |
| 28 | 6 | Clock
| Aug. 9 | 5 | faster.
| 15 | 4 |
| 20 | 3 |
| 24 | 2 |
| 28 | 1 |
| 31 | 0 |
| |------------|
| Sept. 3 | 1 |
| 6 | 2 |
| 9 | 3 |
| 12 | 4 |
| 15 | 5 |
| 18 | 6 |
| 21 | 7 |
| 24 | 8 |
| 27 | 9 |
| 30 | 10 |
| Oct. 3 | 11 |
| 6 | 12 |
| 10 | 13 |
| 14 | 14 |
| 19 | 15 |
| 27 | 16 | Clock
| Nov. 15 | 15 | slower.
| 20 | 14 |
| 24 | 13 |
| 27 | 12 |
| 30 | 11 |
| Dec. 2 | 10 |
| 5 | 9 |
| 7 | 8 |
| 9 | 7 |
| 11 | 6 |
| 13 | 5 |
| 16 | 4 |
| 18 | 3 |
| 20 | 2 |
| 22 | 1 |
| 24 | 0 |
| |------------|
| 26 | 1 |
| 28 | 2 | Clock
| 30 | 3 | faster.
|__________|____________|

* * * * *

THE OCELLATED PHEASANT.

The collections of the Museum of Natural History of Paris have just been enriched with a magnificent, perfectly adult specimen of a species of bird that all the scientific establishments had put down among their desiderata, and which, for twenty years past, has excited the curiosity of naturalists. This species, in fact, was known only by a few caudal feathers, of which even the origin was unknown, and which figured in the galleries of the Jardin des Plantes under the name of _Argus ocellatus_. This name was given by J. Verreaux, who was then assistant naturalist at the museum. It was inscribed by Prince Ch. L. Bonaparte, in his Tableaux Paralléliques de l'Ordre des Gallinaces, as _Argus giganteus_, and a few years later it was reproduced by Slater in his Catalogue of the Phasianidæ, and by Gray is his List of the Gallinaceæ. But it was not till 1871 and 1872 that Elliot, in the Annals and Magazine of Natural History, and in a splendid monograph of the Phasianidæ, pointed out the peculiarities that were presented by the feathers preserved at the Museum of Paris, and published a figure of them of the natural size.

The discovery of an individual whose state of preservation leaves nothing to be desired now comes to demonstrate the correctness of Verreaux's, Bonaparte's, and Elliot's suppositions. This bird, whose tail is furnished with feathers absolutely identical with those that the museum possessed, is not a peacock, as some have asserted, nor an ordinary Argus of Malacca, nor an argus of the race that Elliot named _Argus grayi_, and which inhabits Borneo, but the type of a new genus of the family Phasianidæ. This Gallinacean, in fact, which Mr. Maingonnat has given up to the Museum of Natural History, has not, like the common Argus of Borneo, excessively elongated secondaries; and its tail is not formed of normal rectrices, from the middle of which spring two very long feathers, a little curved and arranged like a roof; but it consists of twelve wide plane feathers, regularly tapering, and ornamented with ocellated spots, arranged along the shaft. Its head is not bare, but is adorned behind with a tuft of thread-like feathers; and, finally, its system of coloration and the proportions of the different parts of its body are not the same as in the common argus of Borneo. There is reason, then, for placing the bird, under the name of _Rheinardius ocellatus_, in the family Phasianidæ, after the genus _Argus_ which it connects, after a manner, with the pheasants properly so-called. The specific name _ocellatus_ has belonged to it since 1871, and must be substituted for that of _Rheinardi_.