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inter se, and the association of some of these differ- Elementary Electrical Engineering in Theory and ences with differing seasons and climates. Many

Practice. By J. H. Alexander. Pp. xii + 20€. large additions exhibiting striking variations of these

(London : Crosby Lockwood and Son, 1906.) kinds are recorded in the descriptions given of collec- It is difficult to find much in this book to recominend tions of butterflies received from South Africa, so

It is evidently not intended for the higher classes of wonderfully rich in these varied forms, as well as from

students or engineers, but this fact is scarcely

sufficient to warrant an entire absence of logical New Zealand, the islands of the Indian Ocean, and

sequence or method in the arrangement of the elsewhere.

material. The scope of the book is far lou wide, Special arrangements made at the museum for the taking in as it does fundamental principles, measurstudy and illustration of mimicry in various orders ing instruments, electrical machinery, batteries, cables, of insects are described. All the orders receive atten

transmission, and generating stations. tion and study there, and with such an affluence of

Such a wide range compressed into two hundred

pages must inevitably lead to a superficial grasp of contributors from all parts of the world, with the

the subject. For instance, what can be the utility 01 aid of the numerous willing and capable helpers to such a paragraph as the following? whom Prof. Poulton heartily acknowledges the “Storage cells are always fixed up in a separato obligations that science owes them, and with the

Brickwork or stone, laid in cement and conenthusiastic and intelligent interest in the subjects

crete, are used for the foundations for the machinery

The coal bunkers should allow of a store of coal that manifestly prevails in every department of the institution, the Hope Museum is plainly pursuing

supply for three or four weeks."

The author would be well advised to concentrate a career that is rendering it of great and increasing his attention on one of the sections mentioned above scientific value.

F. M. instead of attempting to include in a single volume so

much that cannot adequately be treated in so small a

space. OUR BOOK SHELF. Insect Pests of the Farm and Garden. By F. Martin-Immanuel Kants Grundlegung zur Metaphysik der Duncan. Pp. vii + 143;

illustrated. (London :

Sitten. Dritte Auflage. Edited by Karl Vorlander. Swan Sonnenschein and Co., Ltd.) Price 25. 6d.

Pp. XXX + 102. (Leipzig : Verlag der Durr'schen net.

Buchhandlung, 1906.) Price 1.40 marks. This little book appears in the Naturalists' Library This is the third edition of one of Kant's best-known Series. It deals with a number of common insects works in the excellent series of the Philosophische that are destructive in the field and garden, and at Bibliothek. The introduction contains a well-informed least one rare one. The printing and illustrations are account of Kant's occupation with ethical subjecte good on the whole, and it is clearly and interestingly between the years 1764 and 1785, and of the interest written. There are, of course, printer's errors, such excited by the publication of the “Grundlegung." as Brachus for Bruchus, Centorhynchus for Ceuto- | The text is based on the best authorities, and variant rhynchus, ovae for ova, &c. A few illustrations are readings are added in the footnotes. A full index o scarcely recognisable, such as that of the codling names and subjects completes the volume. moth (Fig. 38), the currant gall mite, and the gooseberry red spider (the currant mite, evidently copied from the Board of Agriculture leaflet, being par

LETTERS TO THE EDITOR. ticularly poor, and quite unlike the actual acarus).

When one reads the part dealing with treatment [The Editor does not hold himself responsible for a piroes the impression is at once formed that the author is expressed by his correspondents. Neither can he undertake not only not practically acquainted with the subject,

to return, or to correspond with the writers of, Peyerled but is not au fait with any up-to-date work.

No

manuscripts intended for this or any other part of NATLEI. mention is made of the most important insecticides,

No notice is taken of anonymous communications.] &c., such as arsenate of lead, which is superseding The Mixed Transformation of Lagrange's Equations Paris green, caustic alkali wash, bisulphide of carbon, &c., whilst many of the receipts given are quite out

RETURNING to Padua after a month's absence, I read in of date.

NATURE of August 2 (p. 317) a letter by Mr. A B. Base Such advice as picking up maggotty apples, the

" The Mixed Transformation of Lagrange's Equzcleaning of hop poles, and burning the bine, &c., will scarcely meet with the approval of farmers, and is by G. H. B.'"in Nature of July 10 (p. 205) that the

The letter begins :-“I should fancy from the revieer certainly not necessary. One does not now see many

papers of Prof. Levi-Civita relate largely to the mise hop-poles about to clean. Nothing up to date is given transformation of Lagrange's equations, the complete concerning wireworm, whilst, on the other hand, theory (Proc. Camb. Phil. Soc., vol. vi., p. 117. Hydropeople are cautioned against having animals and dynamics,' vol. i., p. 171) of which was first given by fowls in orchards sprayed with Paris green; the author myself so far back as 1887"; it is then shown that the evidently knows nothing of the experiments carried mixed form of Lagrange's equations may be obtained in out which show that we can safely keep stock of all the most simple way through an elegant artifice of kinds in the orchards even when they are actually elimination. being sprayed.

The words here quoted give the impression that my Some of the scientific names used are wrong; that papers deal principally with the announced theory, and of the celery fly is not Tephritis onopordinis; the

ihat they may be little more than the reproduction of names of the diamond-back moth and the red spider

some previous papers by Mr. Basset. I wish, bowever, the

readers of NATURE to know-and Mr. Basset will be the of hops are also wrong.

first to recognise the fact--that the case is quite different. The work has evidently not been compiled from The papers in question (as it appears from thr general sufficiently up-to-date material to recommend it to the title, "Sur la Recherche de Solutions particulières de: notice of practical men, and there is nothing new in Systèmes différentiels et sur les Mouvements stationnaires," it of scientific value.

and as it seems to me to result also from the review by

on

tions."

"G. H. B.'') are essentially dedicated to the effective

FLASHLIGHT PHOTOGRAPHS OF WILD research of particular solutions of dynamical equatio is. Not a word is said of transformations, mixed forms, &c.,

ANIMALS. and aign oratione di coordinates is mentioned only in the FROM: the popularity of this well-known work preface, because this Routh's of view in

und ” ( and studying the stationary motions.

translation, “ With Flashlight and Rifle "), there is,

T. Levi-CIVITA. we believe, a very general impression that Mr. C. G. University of Padua, August 29.

Schillings was the pioneer in the practice of photo

graphing big game animals by night in their native I do not recollect by whom the phrases “ignoration of

haunts by combining the use of the flashlight with Coordinates ” and “ignored coordinates" were originally the camera. It appears, however, from a most introduced, but on consideration I am of opinion that they interesting and profusely illustrated article in the July are singularly inappropriate ones, and I much prefer the number of the National Geographic Magazine that phrase " kinosthenic coordinates."

the true claimant to this position is an American The advantages of the mixed transformation are that, whenever a generalised momentum is known to be constant the motion can be determined without knowing anything about the coordinate or the velocity corresponding to this momentum. The first trace I can find of this idea is contained in a paper published by Lord Kelvin about 1872 (see “Hydrodynamics," vol. i., p. 177).

The discovery of the mixed transformation was the result of certain hydrodynamical investigations relating to cyclic irrotational motion, but the circumstance that I originally published it in a hydrodynamical form may have obscured the character of the result as a general theorem of dynamics.

A. B. BASSET. September 4.

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The alleged Triassic Fcraminifera of Chellaston, near

Derby. IN NATURE for July 26, in a notice of Mr. FoxStrangway's memoir on the Loughborough district, reference is made to certain Foraminifera of Liassic type, at one time believed to come from the local Trias. Prof. Rupert Jones, F.R.S., has kindly directed my attention to his explanation of the matter in the “ Foraminifera of the Crag," part ii., p. 161, published by the Palæontographical Society in 1895. He there gives a history of the observations, including personal inquiries, and believes that the Foraminifera in question came from Liassic clay in Leicestershire, which was inadvertently thrown in with the red clay'on its journey to Cubitt's works in London." Mr. Fox-Strangways gives a reference to this passage, but does not quote it, and suggests on his own part that the Foraminifera may have come from Liassic material in the drilt.

GRENVILLE A. J. COLE.

66

White. and Brown-shelled Eggs. Birds which lay their eggs in comparatively unprotected places and in a hollow in the ground, as is the case with the pheasant, partridge, jungle fowl, &c., always lay coloured eggs closely resembling in tint the colouring of their surroundings. White-shelled eggs are laid only by birds which make a good nest—those which make it in a secluded spot, or which take the precaution of covering their uggs with leaves, &c., when they are off the nest. It is a strange fact, therefore, that the non-sitting breeds of our domestic fowls lay white-shelled eggs, whereas in the eggs of the sitting or Asiatic breeds the protective colouring is retained in the shell of the egg.

This loss of colour

Fig. 1.-A White-tailed Deer watching a light on bushes in the distance.

From the National Geographic Magasine. cannot be merely the result of centuries of domestication, or all breeds of domestic fowls would lay white-shelled aggs. The systematic repression of the maternal instincts sportsman, the Hon. George Shiras. With regard to of the hen carried on by man for a number of years has his position in the matter of flashlight-photography, certainly produced the white-shelled egg. It would almost Mr. Shiras writes as follows: appear to be the case that the hen, knowing she will have “ While a number of the present illustrations were nothing to do with the hatching and rearing of the chicken taken in the daytime, this method of photography is in the egg, loses all interest in the egg, and leaves it, as

now so well known that I will not attempt to describe it were, to its fate. For this reason she neglects in some

such pictures in detail; but in view of the fact that I mysterious way to impart to the shell the protective colouring which is so necessary, in a state of nature, for the

was the first to attempt flashlight pictures of wild preservation of her race. If this be really the case there

game, and for the first fifteen years was the sole is an insurmountable obstacle in the way of obtaining occupant of this attractive field of photography, it may brown eggs from the non-sitting breeds of domestic hens,

be of interest to the readers of this article to learn and poultry keepers are only wasting time in trving 10 something about this rather odd way of picturing accomplish the impossible.

L. M. F. wild animals."

One of the author's most successful plans in the its own portrait, and here again we may quotett forests of North America was to mount his apparatus author's own phraseology :in the bow of a boat manned by a selected crew, and “ A string is passed across a runway or other peint then to set forth in search of his quarry. Describing where the deer are likely to pass, which, wher, the photographing of a deer the presence of which touched, sets off the trigger and ignites the maghas been made known by the light reflected by his nesium powder. The same method can be used for eyes, the author writes that “The flashlight-apparatus laylight pictures, except that here a slender black has been raised well above any obstructions in the chread is laid across the path, one end of which is front of the boat, the powder lies in the pan ready attached to the shutter of the camera. The shutter to ignite at the pull of a trigger; everything is in revolves as soon as there is any pressure upon the readiness for immediate action. Closer comes the thread, and a picture of any passing object is takers boat, and still the blue translucent eyes watch it. ... | instantaneously. Not the least interesting part of

this species of photography is that the operator does not know until he develops his plates what manner of beast, bird, or reptile has caused the shutter to open."

Although many of the portraits thus obtained are not in every de tail satisfactory to the naturalist, yet they frequently reveal the animal in characteristic and unsuspected attitudes, or display peculiar alarm-features, such as the expansion of the hairs of the light rump-patch of the wapiti revealed in one of the author's pictures. Such pictures are indeed especially valuable in the case of many of the smaller mammals, the nocturnal habits of which make it so difficult to become acquainted with their mode of life.

Whether photography-flashlight or otherwise—will, as the author and Sir Harry Johnston (in the introduction to the English edition of Mr. Schillings's book) hope, ever induce sportsmen to be satisfied with pictures instead of the lives of their quarry remains to be seen.

R. L.

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A SEARCH FOR A BURIED

METEORITE.
THE
HE mode of origin of a re-

markable terrestrial feature, known as Coon Butte or Coon Mountain, has been the subject of much speculation and study, of which an account was given in the year 1895 to the Geological Society of Washington by Mr. Grove Karl Gilbert, of the United States Geological Survey, in a presidential

address entitled “The Origin of FIG. 2.- A Raccoon taking his own portrait. Froun the National Geographic Magazine.

Hypotheses."

This so-called mountain, situ

ated in Central Arizona, rises Suddenly there is a click, and a white wave of light only 130 to 160 feet above the surrounding plain. breaks out from the bow of the boat-deer, hills, When climbed, it is found to contain a crater 530 trees, everything stands out for a moment in the to 560 feet deep, the dry bottom being thus 400 feet white glare of noonday. A dull report, and then a below the level of the land surrounding the rim. veil of inky darkness descends. Just a twenty-fifth of The crater is almost exactly circular, and is nearly a second has elapsed, but it has been long enough to three-quarters of a mile across, two diameters at trace the picture of the deer on the plates of the right-angles with each other measuring 3654 and cameras, and long enough to blind for the moment 3808 feet respectively. From the crest of the rim the eyes of both deer and men. Some place out in the to a distance of about three and a half miles outdarkness the deer makes a mighty leap; . . . and wards the surface of the country is strewn with soon he is heard running, as only a frightened deer fragments of sandstone of various colours; for the can."

first half-mile the fragments are large blocks, som A variation of the plan is to let the creature take of them of enormous size, 60 or even 100 feet il

enormous

diameter; for the next half-mile the fragments are there. Further, he made a delicate magnetic survey smaller and less plentiful; beyond this distance they of the district; no magnetic disturbance being disare isolated from each other, and become smaller and coverable, he concluded that no mass of iron large less frequent as the distance from the crater increases. enough to have produced the crater could be lying

In 1886 some shepherds encamped on the slopes within some miles of the earth's surface, whereupon of Coon Mountain found among the rock-fragments he renounced the asteroidal hypothesis, and accepted on the rim some lumps of iron, which they mistook, the explanation which had been given by his colleague. as is not infrequently the case, for native silver. Some years later the crater and the speculations as The general distribution of the - fragments and the to its origin became known to Mr. D. M. Barringer nature of their material suggested to the shepherds and Mr. B. C. Tilghman. They formed the opinion That all the scattered masses, both stony and metallic, that the asteroidal hypothesis had been renounced by had been shot from the crater of the mountain. A Mr. Gilbert on insufficient grounds. In the first place, tew years later some of the metal fell into the hands according to their calculations, there is a great differof the late Dr. A. E. Foote, of Philadelphia, for whom ence between the volume of the crater and that of it was analysed by Prof. G. A. Koenig, of that city. In the fragmental material; in the second place, the structure and chemical composition the metal proved absence of magnetic disturbance may be due to the to be identical with ordinary meteoric iron, but of asteroid having been broken up into smaller masses, exceptional interest as enclosing microscopic diamonds. each of them polarised, and each having its magnetic Since that time the celestial origin of the iron masses axis in an accidental direction. So convinced were found about Coon Mountain has been recognised as they that in 1903 they “ located " the mountain under bevond doubt, and the meteorite has become well the United States Mineral Land Laws, and at great known under the name of Cañon Diablo, small masses expense proceeded to sink shafts and make bore-holes having been found in the cañon of that name distant with the hope of finding the buried asteroid. The about two and a half miles from the mountain. results of this work, so far as it has yet gone, were During the oral discussion which followed the read recently recorded in two papers published in the ing of the paper of Dr. Foote on August 20, 1891, Proceedings of the Academy of Natural Sciences of before the American Association for the Advancement Philadelphia (December, 1905). One of them has of Science, Mr. Gilbert, who chanced to be present, been written from the point of view of the geologist suggested that the fall of the iron masses might have (Mr. Barringer), the other from those of the physicist, been connected with the formation of the crater, and chemist, and mathematician (Mr. Tilghman). The that the large hole might have been caused by the former says :-“ They do not leave in my mind a penetration of the earth by an

iron scintilla of doubt that this mountain and its crater meteorite, perhaps 1500 feet in diameter, large enough were produced by the impact of a huge meteorite to be termed an asteroid. In such case the asteroid or small asteroid”; the latter feels that “he is is buried in or near the hole and probably at no justified, under due reserve as to subsequently degreat depth.

veloped facts, in announcing that the formation at Not being at that time at liberty to visit Coon this locality is due to the impact of a meteor of Mountain himself, Mr. Gilbert asked his colleague, enormous and unprecedented size.” Mr. Willard D. Johnson, to examine the district and It may be mentioned that a few years ago a suctry to discover what had been the mode of origin of cessful search was made by Finnish geologists for the crater. On his return Mr. Johnson reported that a large meteorite which was believed by them to the crater had probably been produced by a have buried itself within a certain area. But in that mendous steam explosion, the fragmental material case the presumptive evidence was very strong. A around being the original contents of the hole. meteor had lighted up a large extent of the country, Within a radius of fifty miles there are hundreds of and the next morning a newly made hole, with cracks vents, from which lava has issued during the later radiating from it in various directions, had been geological periods, and thus there existed at one time found in the ice covering the Baltic Sea, near Bjurd neighbouring mass of molten material sufficient böle, in Finland. After a patient search the mass to account for the production of the required amount was at last located at a considerable depth below the of steam. In such case the fall of the masses of iron sea-bottom, and eventually extracted. What are the had been independent of the formation of the crater. prospects of a similar success at Coon Mountain ?

The rocks in the region containing the crater, how- For many miles round the crater the order of surever, are stratified and of sedimental origin, and the cession of the rocks, beginning at the surface, is as strata, except at the hole itself, are still quite hori- follows: rontal. They are of late Carboniferous age, and con- (1) Red sandstone, 20 to 40 feet thick. sist, to a considerable depth, of coloured sandstones, (2) Yellowish (calcareous) sandstone, 200 to 350 feet. one kind being so calcareous as to have claims to be (3) Whitish sandstone, probably 400 to 500 feet. pe garded as a limestone. But all round the hole (4) Yellow sandstone, thin layer. itself the strata have been bent, and are now directed (5) Reddish-brown sandstone. more than 1000 feet. upwards, approximately towards the same point. The uppermost stratum has been largely eroded, and

This explanation and report being of an extraor- remains only as widely separated flat-topped buttes dinary character, Mr. Gilbert's interest in the problem scattered about the plain. became even greater than before, and he soon seized This upper stratum of red sandstone still existed at in opportunity of making an examination himself. the place at the time when the crater was formed, This was done with such minuteness that he was for it is the material of the upper part of the rim. able to draw contour lines of the crater and district It has been raised 140-180 feet above its original for every ten feet of difference of level, and could position. The upper part of the interior of the crater form an approximate estimate as to the positions consists of sandstone cliffs, the lower part of talus. of the contour lines at the time the crater had been The lower portion of the latter is covered with horiformed; hence he was able to calculate the respective zontally stratified sediments having a total thickness volumes of the crater and the fragmental material. of 60 100 feet and a nearly level upper surface of He came to the conclusion that the two volumes were circular outline and 1800 feet in diameter. The virtually equal (eighty-two millions of cubic yards), material must have settled in a shallow fresh-water and thus that no asteroid could have buried itself | lake once occupying the crater.

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The fragmental material of the rim consists of lowing remark made by the late M. Daubrée was the débris of the strata in which the crater has been published by him in 1879, before Coon Mountain had formed, the blocks being piled one upon another in been heard of, and is also suggestive (“ Géologie Ex: the utmost confusion. Further, there many périmentale," part ii., p. 645) :-“ In the deep and millions of tons of pulverised sand-grains, much of hot portions of the globe, for instance in volcanic the material being an impalpable powder. It con- reservoirs, water is present under enormous pressure. stitutes a great part, not only of the rim, which is The pressure of that which forces lava up to the three miles in length round the base, but also of summit of Mt. Etna must certainly exceed the bottom of the crater, for it has been found by atmospheres. It is therefore quite comparable with means of bore-holes to extend to a depth of more the tension developed in the chamber in which these than 850 feet.

experiments have been made. When water escapes The masses of meteoric iron, being of pecuniary to the surface by narrow fissures in such circumvalue as specimens, have been much sought for, and stances, it must bring different substances into a masses small and large, amounting altogether to state of pulverisation simulating that of volatilise about fifteen tons, have been found among the upper tion." blocks on the rim, and on or near the surface of Two other observations are relied on by the authors the surrounding plain in all directions from the in their support of the asteroidal hypothesis. Accordcrater; none have been found within the latter. ing to the first observation, obstacles at a great depth Several masses weigh from 600 lb. to more than

and probably of smail size were found to interferp 1000 lb. Mr. Gilbert states that some of the iron has with the boring. They were inferred, chiefly from been found outside the range of the rock débris, one their hardness and from the difficulty of removal of large mass being as much as eight miles distant from a magnet let down to the bottom of the bore-hole, the crater. There have also been found lumps of to be probably metallic iron, and to be parts of the oxide of iron, in great quantity and having a similar broken asteroid. But the presence of some small distribution to that of the metal. Mr. Gilbert (and masses of iron beneath the crater is to be expected if also Dr. Foote) regarded them as also being of all the masses were lying embedded in the sandstone meteoric origin, and as perhaps having resulted from before the crater was formed. Those which were prothe weathering of a particular constituent of the i jected nearly vertically upwards must have fallen back meteorite, namely, the protosulphide of iron; but Mr. into the large hole and be deep down among the Barringer and Mr. Tilghman have found that they : débris. According to the second observation, contain much nickel, and that many of them consist ' stratum at a considerable depth contains small parinternally of magnetic oxide of iron, sometimes itself ticles of oxide of iron thought to be of meteoric origin. containing a nucleus of meteoric iron. Mr. Barringer, , The same kind of material is said to occur on the like Dr. Foote, suggests that the magnetic oxide' surface of the surrounding country for several miles. resulted from the combustion of the iron when the The material in which these small particles of oxide meteorite was travelling through the air, but in the are distributed in the crater must either be in situ or opinion of the present writer all the oxide, mag- , have fallen back into the hole: in the former case netic or not, is a result of weathering. There has they cannot be of meteoric origin, for small particles been plenty of time for this action, for cedars now would not have had the requisite penetrative pon er: 700 years old are growing on the rim of the moun- in the latter case, it is probable that they were lving tain. Further, the masses of iron found on the surface near the surface before the steam-explosion, and fell of the plain must have penetrated the earth to some back with the fragmental material into the hole. depth at the time of the fall, and have been since It is found as a matter of experience that meteorites exposed by denudation of the penetrated material. ' on striking the ground have a comparatively small The authors roughly estimate the fall to have taken velocity-only a few hundreds of feet a second. I place not more than 3000 years ago, perhaps much it possible that an asteroid after passing through the less.

earth's atmosphere could retain a velocity large Though all the masses of iron found in the rim enough for the production of such a crater? Applyhave been got from the surface, lumps of the meteoric ing a method devised by Schiaparelli and numerical oxide have been met with to a depth of 27 feet, data obtained from artillery experiments, the present and this is of interest because some of them were writer has made some calculations as to the velocity lying beneath big blocks of sandstone, through which, of a meteoritic ball on reaching the ground, the baal! whether as metal or as oxide, they could not have being supposed to have a specific gravitv seven times passed. They must have taken up their present posi- that of water, to have entered the earth's atmosphere tions at the same time as the blocks themselves. To at a speed of fifty miles a second, and to have travelled the present writer it seems probable that they had vertically. Neglecting the small additional velocit been buried, possibly a long time, in the upper layers due to the action of gravity for the few seconds of of sandstone, and were ejected with the rock-frag- flight, and the diminution of size of the ball during ments when the crater was formed, but Mr. Barringer the flight, the numbers are as follows :explains them as fragments which had been broken

Radius of ball

Final velocity from the asteroid during its passage through the air,

in netres had diverged from the path of the meteor, and had

694 while still burning become entangled, and afterwards

2300 smothered, among the blocks of sandstone and minute

8261 débris projected into the air through the penetration

25,461 of the earth by the main mass.

According to Mr. Gilbert, it has been found in Is for the enormous amount of pulverised silica, artillery experiments that a spherical projectile veris the authors hold that it cannot have been produced ing solid limestone with a velocity of 1860 fert a otherwise than by the action of an enormous pro- second will penetrate to a depth of something less jectile penetrating the sandstone. But it is difficult than two diameters. It would appear, then, that a

see why the crushing of the grains could not meteorite of large size would not be prevented by have been produced by an enormous pressure of the earth's atmosphere from having a penetratisr steam, such as must have preceded, according to effect sufficient for the production of such a crater. Mr. Johnson, the formation of the crater. The fol

L. FLETCHER

21

in metres

OI

I.O 10.0 100.0 1000.0

to

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