gist in charge of the anthracite division of the Second geological survey of Pennsylvania, are a very close approach to this theoretical perfection. They are devoted to the illustration of the Panther Creek coal-basin, the north-eastern portion of the southern anthracite field, included between the Little Schuylkill River on the west, and Mauch Chunk on the east. Of these charts, one sheet gives the reproduction of a topographical map of the basin, made by Mr. R. P. Rothwell in 1869, on a scale of 1,600 feet to the inch, with contour-lines at vertical intervals of 10 feet. Three sheets, forming but one map, show the shape of the floor of the mammoth coal-bed, on a scale of 800 feet to the inch. This is practically an underground map; and in it Mr. Ashburner has introduced the somewhat novel system of representing the shape of a certain bed in the basin by contours, in the same manner as the surface of the ground is represented in our grade-curve maps. These underground curves are printed in red, and are drawn at 50-feet vertical intervals; some of the prominent surface features, such as railroads and important buildings, being printed over them in black.

It seems a pity that Mr. Rothwell's map should not have been published on the same scale, so that it might be superposed upon the underground map; thus showing, at a glance, the difference between surface and underground topography. Such a map shows at once the shape of the basin, and, by the relative closeness of contour-lines, the angle of dip at any point; and from it may be constructed an actual section of the coal-basin on any given line. Twelve of such sections are actually constructed at favorable points, and represented on three other charts on a scale of 400 feet to the inch. They are also given on the same charts on a scale of 1,500 feet to the inch, drawn one under the other, so as to represent more graphically the general shape of the various folds, and the position of the underlying rocks. They are accompanied by a sketch-map of the whole basin on a scale of 2,300 feet to the inch.

On still three other sheets are given columnar sections, representing the thickness of the coal and intervening beds at a number of different points where they have been determined, constructed on various scales, from 10 feet to 300 feet to the inch. One of these sheets also contains a skeleton map of the basin, showing the locality of these sections as well as of the cross-sections.

Furnished with these maps, the mine-owner I can tell at what distance a shaft or tunnel

may reach the coal-bed from any given point, and the inclination of such bed when reached. He can determine the proximate line of the bottom of the various synclinal basins along which he wishes to run his galleries, and which coal from the various breasts may reach by gravity.

Of the three remaining sheets of the series, one gives a diagram showing, in different shades of color, the area of the respective coalbeds, developed on beds, developed on a horizontal plane; the second, a skeleton map of the entire anthracite region on a scale of 300000, with columnar sections showing the local names of the various coal-beds in different parts of the region, and the names of all the collieries. The third sheet shows the production of anthracite coal, from its earliest development to the present day, both in columns of figures from different districts, and in curves forming a pyramidal diagram for the total product; also some brief historical notes.

The sheets are 26 by 32 inches in size, and are engraved by the reliable firm of Julius Bien & Co. They bear evidence of an immense amount of accurate detail-work; and the only serious criticism we have to make, is the use, by Mr. Ashburner, of the magnetic instead of the true meridian.

The practical value of such maps as these, where underground developments have been. carried on to a sufficient extent to furnish data which will make their deductions trustworthy, must be evident to the most untechnical; and that it has been appreciated by the mine-owners of the anthracite region is proved, not only by the practical aid they lent to the work by furnishing all their surveys and measurements, but also by their contributions of money to help defray its expenses. They form a highly instructive lesson of the practical value of a properly conducted geological survey, and one to which the legislators of Massachusetts and Rhode Island would do well to turn a listening ear; for it is certainly a disgrace, in these enlightened times, that they have within the borders of their states a coal-basin of which less is known than of those of the wild, almost uninhabited, regions of the Rocky Mountains.

THE SMITHSONIAN PUBLICATIONS. Catalogue of publications of the Smithsonian institution, 1846-82, with an alphabetical index of articles. By W. J. RHEES. Washington, Smithsonian institution, 1882. 14+328 p. 8°.

A PREFACE states in a general way what the institution has published, the rules for distribu

tion, and the prices of those numbers which are sold. A detailed chronological list of the 496 issues is then given, followed by a classified list under 29 heads, with some subdivisions, and, finally, by an alphabetical index to the Contributions, Miscellaneous collections and Reports of the Smithsonian, the Bulletins and Proceedings of the National museum, and the First annual report of the Bureau of ethnology. Thus every inquiry that will probably be made is answered beforehand. Is my set complete? Is this volume perfect? What articles are there in this department of science? In what volume or volumes has this man written? In what is this subject treated? How can I get them? How can I procure a set, or get the volumes as they are issued? Indeed, if one must be critical, we should say that answers are provided for some questions which only an idiot could be expected to ask. In the index, not only are references made from the names of the authors, and from the subjects of articles, but from the first words of their titles, however insignificant they may be. Thus we have such entries as Contribu

tions to history of fresh-water algae, Criticisms of Dr. J. Hahn, Hints on public architecture, Knowledge of cryptogamous plants, Means of destroying the grasshopper, Method of preserving lepidoptera, Narrative of the Hassler expedition, and scores of others just as unworkmanlike as these, entries that would make the Index society stare and gasp. In an ordinary book this might be overlooked; but it is unworthy of one which is intended to be one of the monuments of the scientific achievements of our country. It is true, these articles are all indexed in their proper places also; so that the fault is, at worst, one of surplusage. We have seen indexes in which entries were made under A and The, and there only. Mr. Rhees has not reached this length of absurdity. He may urge that there are people who will look for the articles under the words to which we have objected. It is difficult to over-estimate the mental left-handedness of mankind, but Mr. Rhees is addressing a scientific public. We should be sorry to believe that their training had produced no better habits of thought than he seems to anticipate.

ASTRONOMY.

Spectroscopic observations of the transit of Venus. Tacchini at Rome observed the first and second contacts by means of the spectroscope, in the manner first proposed by Young in 1869. He saw the external contact 54 seconds earlier than his colleague Milosevisch, who observed with a telescope in the ordinary way: the second contact (internal) he observed 36 seconds earlier. A discussion shows that the spectroscopic observations are superior in accuracy to the telescopic. An attempt was made to observe the contacts at Palermo in the same way by Riccó, but it failed. At the moment when the planet left the chromosphere, and its atmosphere was on the slit of the spectroscope, both Tacchini and Riccó saw, for a fraction of a second, one or two bands between B and C, which could only have been caused by the planet's atmosphere. - (Mem. spettr. Ital., Dec., 1882.) C. A, Y.

[636

Observations of the lunar crater Plato. — A comparison by A. Stanley Williams of a large number of observations taken by himself and others in 1879-82 with a similar series taken in 1869-71 seems to give evidence of change in this crater. Of thirtyseven spots seen in the crater in 1869-71, six were not seen in 1879-82; while seven, not seen during the first period, were seen in the second. The mean visibilities of most of the spots observed in both series agree very closely, but eight show a decided variation in brilliancy. Among the light streaks in the crater, some change was noted, particularly in one which was not seen at all during the first twelve months of the first period, and is now larger and brighter than

1

[637

Transformation of surfaces. - Professor Enneper, in this article, has reproduced the substance of two previous articles which he has written upon the same subject, with a number of additions. The particular transformations treated of are defined as follows: the corresponding points P and P1 of two surfaces S and S are so related to a fixed point O, that the plane through the points O, P, and P1 contains the normals to the surfaces S and S, in the points P and P1. Among other derived surfaces coming under this head are the pedal and negative-pedal surfaces, inverse surfaces, etc. A generalization of Malus' theorem is given; viz., the surface separating two homogeneous media is regarded from a given point 0; at a point P of the surface, the ratio of the sines of the incident and reflected rays is a function of the distance O P: the reflected rays are then the normals to a certain surface and its parallel. The author discusses the problem of finding when lines of curvature upon the given surface S correspond to lines of the same kind upon the derived surface S1. The results in this case are tolerably well known. (Math. ann., xxi. 1883.) T. c.

[638

Geodesic polygons. The results obtained by the author, Otto Staude, in this paper, are for the most part known; but his method seems to be entirely new. M. Staude attempts, in a measure, to do for quadric surfaces, by aid of hyperelliptic functions, what has already been done for conics by the aid of elliptic

T. C.

functions. He limits himself to the examination of geodesic polygons traced upon central surfaces of the second degree. Section 3 of the paper is an excursus upon the thread construction (fadenconstruction) of the lines of curvature on quadrices. For an intelligible reading of the paper, a previous paper of the author's, Ueber fadenstructionen des ellipsoides,' must be referred to. (Math. ann., xxi. 1883.) [639 Complexes of the second order. - M. Genty discusses Kummer's sixteen-nodal quartic by the methods of vector analysis. No new results or properties of this surface are given; but the paper is interesting as an application of this particular method. -(Journ. de math., 1882.) T. C. [640 Hypergeometric series. M. Mathieu studies the differential equation of the second order, satisfied by Gauss's function F (a, ß, y, x), and examines briefly the cases when the general solution of this equation can be expressed in a finite form, and obtains, in consequence, the cases when the function F (a, ẞ, y, x) can be expressed in finite form. He determines also the cases when the function F (a, ß, y, sin2 ) is periodic with respect to 9, and has 2 its period. (Journ. de math., 1882.) T. C.

for

[641

Parallel surface to the ellipsoid. - Dr. Craig discusses the general equation of this surface, and its principal sections. Certain of its singularities are enumerated, and formulae are given for the ratios of corresponding elements of area and length upon the parallel and primitive ellipsoid. A number of formulae are given, referring to the curvature of the surface. Elliptic co-ordinates are employed throughout the greater part of the paper. (Journ. für math., xciii.) T. C. [642

PHYSICS. Heat.

Specific heat of water. The results of experiments on the specific heat of water at different temperatures differ, not only quantitatively, but qualitatively. Rowland and Münchhausen, whose experiments are the most reliable on this subject, have shown that the specific heat of water decreases to about 30°, and thence increases. In order to test these results, Hr. F. Neesen has made some experiments upon this subject with Bunsen's ice-calorimeter. The calorimeter was constructed according to the plan of Schuller and Wartha, in order to avoid the errors caused by the impurities of the snow. Hr. Neesen points out that it is of importance not to begin the experiment until some indications of melting appear in the ice of the calorimeter. If this point is not observed, the change of volume will be too small. The thermometers used were two mercury thermometers, graduated respectively to 0.20 and 0.1°. The results obtained by Neesen are to be considered merely approximate, as sufficient determinations of the specific heat at each temperature were not made. The results, however, agree qualitatively, though not quantitatively, with those of Rowland. (Ann. phys. chem., xviii. 3.) [643

C. B. P.

Electricity.

High-pressure electric accumulator. - Mr. Frederick J. Smith describes an arrangement for prolonging the life of a gas-battery. The tubes containing the electrode are inverted in a tank nearly filled with dilute sulphuric acid. The tank is closed airtight, and the gases, as they are evolved, generate a . pressure, which, as shown by a manometer, amounts to several atmospheres by the time the tubes are filled. The amount of gas which can be thus col

E.

the mean length of the wires, diminished by p2- m Hence he deduces two methods of measuring the horizontal intensity of terrestrial magnetism, which he calls the bifilar-galvanic and bifilar-magnetic respectively. The first method consists in observing the deflections a of a magnet, and of a circular coil suspended at a distance a from the magnet, when D tan a H2 = a tan o' subject to certain corrections. The second method consists in observing the deflections a and of two magnets, one large in respect to the d2 22 + a2 a2 2 a3

=

D

other, when H @3 ( 1 + T) ( 1 − 3

sin a tan

2K)

(1 - 2 tan a tan ), where d is the distance be

Boston water-works. - An elaborate description of the additional supply of water for the city of Boston from Sudbury River, compiled by Mr. A. Fteley, the resident-engineer upon the work during its construction, has just been issued by the city government in a large, finely printed, and copiously illustrated volume. The works for supplying Boston with water from Sudbury River consist of three storage-reservoirs in Framingham, and a conduit from that town to Chestnut-hill reservoir in Brookline. In 1881 Sudbury River furnished to Boston more than twice the quantity of water supplied from Lake Cochituate; and steps have already been taken to increase still further the storage-capacity of the system. The volume begins with a discussion of the sources of supply, the rainfall, and the storage-capacity of the reservoirs. Next follows a general description of the dams and reservoirs, and of the several sections of the work, in all its engineering features. The quality of the water, the gauging of the river, and a discussion of the capacity of the conduit, and the flow of water over weirs, conclude the body of the work. The appendix contains valuable tables on water-supply hydraulics, and a large amount of information for the practising engineer. The work is illustrated with 69 large plates, commencing with a map of the Sudbury River watershed, and giving very fully the construc

Anthracite coal-fields of Pennsylvania. - Mr. Charles A. Ashburner read a paper on a new method of estimating the contents of highly-plicated coalbeds, as applied to the anthracite fields of Pennsylvania. The questions of the future production and ultimate exhaustion of these fields are of the greatest importance. In 1860 the population of the United States was 31,443,321, and 8,513,123 tons of coal were produced; i.e., actually shipped to market. In 1870 the population had increased twenty-two per cent (38,558,371), and the production of anthracite was nearly doubled, being 16,182,191 tons. For the year 1880, with a population of over 50,000,000, the product was 23,437,242 + tons. In 1882 the actual production was over 30,000,000 tons. It has been variously estimated that the 470 square miles containing this coal in Pennsylvania will be entirely exhausted in from 140 to 204 years. While Mr. Ashburner does not estimate the ultimate exhaustion, he has devised a method for estimating the contents of these fields from data now being obtained by the careful and practical geological and mining examinations of the state survey. The exact position and detailed structural shape of the coal-beds are first mapped by fiftyfeet contour-lines along the floor of the beds, giving, completely and satisfactorily, their geometrical construction and shape. These surfaces are then developed into planes by the development into straight lines of the line of the bed, as cut by paralleled sectionplanes 1,600 feet apart. This graphical method is attended with errors which are mathematically discussed, and which have been formulated by Mr. Arthur Winslow. This method does not give the true area of the surface of a sphere, cone, or triangular trough. In the case of a sphere, it gives of the 4 true area; in a cone, the error increases directly as the secant of the angle which the pitch of the cone makes with its axis; and in a triangular trough, which more nearly represents the shape of the anthracite basins, the error is very much less. A practical test has been made of this method in the Panther Creek basin, between Mauch Chunk and Tamaqua; and the maximum possible error in estimating the surface-area of the coal-beds was found to be .905 of 1 per cent. After the areas are thus found, the contents are obtained by careful measurements made in the mines to ascertain the actual number of tons of coal which are contained in a unit (one acre) of bedarea. In this way it has been estimated that the above basin originally contained 1,032,000,000 tons; that the area under development originally contained 92,000,000 tons, out of which latter area 54,000,000 tons have been taken. (Eng. club Philad.; meeting March 17.)

CHEMISTRY.

(Analytical.)

π

[647

Determination of organic matter in potable water. In an extended examination of the various methods in use for determining the purity of potable water, undertaken by Prof. J. W. Mallet for the National board of health, special attention was given to the combustion process' of Frankland and Armstrong, the albuminoid-ammonia' process of

Wanklyn, Chapman, and Smith, and the 'permanganate' process suggested by Forchhammer. Prof. Mallet finds that it is unsafe to base conclusions on a single determination by the combustion process; and the evaporation should be conducted by means of steam, in such a manner as to preclude the possibility of absorption of ammonia from the atmosphere. It was also found advantageous to conduct the evaporation under diminished pressure at quite low temperatures. In the albuminoid-ammonia and permanganate processes the most desirable results were obtained by keeping the volume of liquid in the retort constant and the permanganate in excess. Prof. Mallet thinks that more importance should be attached to the quantity of nitrites and nitrates than is usually assigned to them; and he finds that they may readily be reduced by phosphorous or hypophosphorous acid. These methods are regarded by him as an insufficient basis on which to reach a decision as to the condition of a water; and they should be made of secondary importance to evidence of a general nature, such as the source and history of the water examined. A thorough biological examination of water polluted in various ways is recommended. (Amer. chem. journ., iv. 241, 334, 426.) C. F. M. [648

Composition of a spring-water from Salzbrunn. In an analysis of a spring-water from Salzbrunn, in Silesia, T. Poleck obtained the subjoined results in 1,000 grms.

Its

Origin of arsenic and of lithium in waters containing calcium sulphate. In examining different natural waters for arsenic, from Martigny, Bachu, and other localities, M. Schlagdenhauffen finds it in quantities varying between 0.0050 grm. and 0.0500 grm. per litre. Since arsenic is found in different varieties of gypsum, the author concludes that it is in the form of calcium arseniate. origin may be traced to the marls, where it existed as sulphide. By the action of acid calcium carbonate, it was probably converted into the sulpho-arseniate, and finally into the arseniate. When certain marls are submitted to the action of hydrochloric acid, the solution evaporated, and the residue extracted with a mixture of alcohol and ether, lithium may readily be detected by the spectroscope. Five grms. of the earth contain sufficient lithium to give a distinct red band. (Journ. pharm. chim., 1. 464.) C. F. M. [650

AGRICULTURE.

Symphytum asperrimum as fodder. This plant is reported to yield a large quantity of palatable and nutritious green fodder, even on poor soil,

Fattening different breeds of sheep.—It is a well-known fact, that, in different breeds of the same species, the same fodder may produce very different effects. All experiments hitherto, however, have failed to show any notable differences of digestive power in such cases; and it would thus appear that the observed differences are due to the varying energy with which the constituents of the body are oxidized. In an experiment with two mature sheep, a southdown and a merino, on identical rations, from which identical amounts of the several nutrients were digested, Weiske found that the apparent gain of 'flesh' (nitrogenous matters) was greatest in the merino sheep; but this difference was somewhat more than covered by the greater growth of wool. So far as this single experiment proves any thing, it shows that not only the digestive powers, but also the proteid metabolism, of different breeds of sheep, are essentially the same, and indicates that the differences in the ease of fattening are due to differences in the rapidity with which non-nitrogenous substances are oxidized in the body. (Journ. landw., xxx. 385.) H. P. A. [652 Valuation of fodders. The commission appointed in Germany in 1878, to devise a uniform method for calculating the money-value of fodders from their chemical composition, held its fourth meeting at Eisenach, Sept. 17, 1882, a report of which is presented by Prof. J. König. An abstract was presented of papers published on the subject since the last meeting of the commission; and this was followed by a discussion of the results thus far attained. Νο final conclusions were arrived at; but it was recommended, that, in such computations, the same price be assumed for crude proteine and crude fat, and that the carbhydrates be estimated at one-fifth the price of proteine. It is expressly set forth that this is only a provisional decision, and further investigations and computations are called for. — (Landw. jahrb., xi. 849.) H. P. A.

[653

Testing milk. Jörgensen proposes to use the index of refraction of milk, or of whey prepared from the milk, as a test of purity, and asserts that it shows comparatively small variations, while even a small addition of water is plainly indicated. Chludsinski considers it necessary to determine the specific gravity of the whole milk and of the skim-milk, and the percentage of cream, in order to judge of the purity of a sample, and describes an instrument for this purpose, the specific gravity being determined by weighing a measured quantity of the fluid.—(Landw. jahrb., xi. 701, 835.) H. P. A. [654

GEOLOGY. Meteorites.

The Bishopville meteorite. Dr. M. E. Wadsworth stated that a microscopic examination showed that the Bishopville meteorite, which fell in March, 1843, was composed of enstatite, felspar, augite, olivine, pyrrhotite, and nickeliferous iron. The enstatite contained many glass inclusions of similar form to the enclosing mineral. Numerous glass inclusions were also seen in the felspar, and many in both minerals were bubble-bearing. Most of the

felspar showed the twinning of plagioclase. Glass inclusions have always been regarded, when found in terrestrial rocks, as indicating igneous origin. The composition and structure of this crystalline stone is like that of the gabbro (norite) variety of basalt. While, according to common custom, the speaker might have proposed a new name for this, he preferred to call it a gabbro or basalt, in accordance with the principles announced in SCIENCE of March 9. Chladnite, he said, was not a pure enstatite, but a crystalline aggregate of enstatite, felspar, augite, and olivine. The well-marked glass inclusions and the structure of this stone had, according to the speaker, an important bearing upon the question of the origin of meteorites, and were in accord with his previously published views. (Bost. soc. nat. hist.; meeting April 4.) [655

METEOROLOGY.

Aurora borealis. Herr H. Hansen's observations of the November (1882) auroral displays in Trondhjem, Norway, show that each continued an extraordinary length of time, especially during the week Nov. 12-18. Every night of this week the heavens were illuminated with the auroral light, while it was seen from 8 P.M. on the 17th till 6 A.M. of 18th. The most striking display occurred on the 18th, at 4.30 A.M., when a brilliant corona appeared in the zenith, from which vivid streams of light stretched to the horizon; while luminous waves flowed uninterruptedly from the latter towards the corona, diffusing so strong a light as to enable one with ease to read moderately clear print. — (Nature, Feb. 8.) [656

H. A. H.

Polar research. - The French magnetic and meteorologic expedition to Cape Horn has taken up quarters at Orange Bay, Terra del Fuego, east side, lat. 55° 31' S. Observations began Sept. 26, 1882. The party found the climate mild, the temperature, up to the time of the report, ranging from freezing to 61°. (Nature, Feb. 8.) H. A. H. [657

PHYSICAL GEOGRAPHY.

Granular structure of glaciers. E. Hagenbach-Bischoff reviews the previous study of this question from Hugi to Klocke (Neues jahrb. miner., 1881, i. 23) and Forel (Arch. sc. phys. nat., 1882, vii. 329), and shows by optical and physical characters that each grain of a glacier is a single crystal of ice. The crystals stand with their axes in all positions, so that their contact surfaces form a very irregular network of polygonal planes. When the ice is broken at a temperature below its freezing-point, the subconchoidal fracture is independent of the crystals; but on melting, the crystals separate along their contact surfaces, as is shown by the planes of penetration of a colored liquid (soluble aniline blue is best). As has long been known, the grains are smallest in the névé, and largest at the end and bottom of the glacier, where one was found measuring 14, 12, and 9 cm. Forel has thought that this growth comes by the addition of infiltrating water, and that the motion of the glacier is thus aided; but this supposes that the ice is porous enough to allow water to enter, and requires a low internal temperature (for an annual increase of 0.043 cubic or 0.014 linear measure, the ice must average -7° C.). Hagenbach-Bischoff contends that certain crystals grow at the expense of their neighbors: as the expansion of a freezing icecrystal is greater along one axis than another, it follows that pressure will lower the melting-point by the greatest amount when directed along the axis of greatest expansion; consequently those crystals whose