24 
NATURE 
[May 11, 1871 

according to the utilitarian or the intuitive theory of 
morality. 
Such vagaries as the above are however rare, and we 
can conscientiously recommend this book as admirably 
adapted to lead its readers to observe for themselves the 
varied phenomena presented by insects, and thus to 
become true entomologists. ALFRED R, WALLACE 

AMERICAN GEOLOGY 
Preliminary Field Report of the United States Geological 
Survey of Colorado and New Mexico. Conducted 
under the authority of the Hon. J. D. Cox, Secretary of 
the Interior. By F. V. Hayden, United States Geo- 
logist. 8vo. pp. 155. (Washington: Government 
Printing Office, 1869.) 
i ee preliminary field report makes us acquainted 
with a vast tract of territory hitherto scarcely 
known, save to the more adventurous squatters and to the 
various tribes of Indians who have gradually been driven 
farther and farther west by the wonderful growth of the 
United States populations, fed as they are annually by 
streams of English, Irish, Scotch, and German emigrants. 
Unfortunately for the Red-skins, they are not only hemmed 
in on the one side by the United States, and on the other 
by the equally vigorous growth of California and its vast 
mining and agricultural population ; but their territory, 
only hitherto invaded by the Mormons and the “ Pony- 
Dispatch,” is now cut in twain by the great Pacific Rail- 
road, which, in its course, has sent forth geological re- 
connaissances right and left, discovering timber here, coal 
there, building stone in this spot, mines in that, until 
there is no space left for them save in the happy hunting- 
grounds above, to which they are fast going, aided by 
revolvers, alcohol, and disease. 
The report relers to a line of country extending from 
British North America to New Mexico in a northerly 
and southerly direction, and from the Rocky Mountains to 
the Lower Missouri in an easterly and westerly one. Dr. 
Hayden explains the reason why he has been able in a very 
short time to cover so large a tract of territory—it is, that 
“there is great uniformity in the geology of the country, 
and when one has become familiar with the different 
geological formations over a small area, he can trace them 
with great rapidity over long distances” (p, 11). 
First, we have the Rocky Mountain system forming the 
main ridges and the hills, composed of granite rocks. 
Resting on the flanks of these more elevated masses, the 
stratified deposits are exposed in succession, becoming 
less and less inclined as we recede from them and enter 
the plains. 
The oldest stratified deposit met with is the Potsdam 
Sandstone, equivalent in geological position to our Upper 
Cambrian, or to the Primordial Zone of Barrande ; this is 
followed by strata of Carboniferous age, but giving no 
promise of workable seams of coal. The Triassic series 
may be represented by certain red arenaceous deposits, 
sometimes containing gypsum and rocksalt ; these pass 
upwards into undoubted Oolitic beds. Next follows a 
Cretaceous formation, some 4,000 feet in thickness, followed 
by a well-developed Tertiary series of vast geographical 
extent, and but very slightly inclined. 

| THE first of these works is the second edition of the first _ 
| follow the planets Mercury, Venus, &c., in order, and | 
These Tertiary beds are rich in lignites, and evidence a 
long period of tranquil estuarine or lacustrine deposition 
in a region supporting dense forests of large trees, and a 
vegetation far exceeding in luxuriance anything now met 
with in these latitudes. Carnivores, Pachyderms, Probos- 
cidea, &c., occur in great abundance. It is very interest- 
ing to know that in Tertiary times North America had its 
elephants, hippopotami, rhinoceroses, horses, lions, &c., and 
was, in the size and abundance of its Mammalia, in no 
way surpassed by the Continents of the Old World. 
Two minor reports accompany Dr. F. V. Hayden’s re- 
port, one on “ Mines and Mining,” by Mr. Persifor Frazer, 
jun., giving a most interesting account of the mining capa- 
bilities of the district; the other on the “Agriculture of 
Colorado,” by Mr. Cyrus Thomas. There is every pro- 
spect of the Colorado territory becoming as rich an agri- 
cultural district as it has already proved to be a mining 
one. H. W. 


OUR BOOK SHELF 
Aunt Rachel’s Letters about Water and Air. 
Longmans and Co., 1871.) 
IN the form of a series of familiar letters from an aunt 
to a nephew and niece, we have here an account, in simple 
familiar language, of some of the commoner physical 
phenomena of nature. Recollecting the books with a 
similar aim that have passed through our hands, we feel © 
grateful to find one free from conspicuous blunders. To 
the little book before us we need not however apply such 
negative praise. It is in all respects to be commended as 
a book to put into the hands of the young. And we fancy 
that even many well-educated people who are not young 
in years, will find a record and explanation of facts with 
which they are not familiar, They may learn here all 
about the formation of ice, latent and specific heat, the 
air-pump, the barometer and thermometer, the winds, 
combustion, and many other phenomena of daily life. A — 
few well-executed woodcuts illustrate the text ; and we 
would like to hear that a large circulation has rewarded — 
the efforts of “ Aunt Rachel” to popularise the elements f 
of science. 
Handbuch der allgemeinen Himmelsbeschretbung vem f 
Stanapunkte der kosmischen Wi eltanschauung darge» 
stedit, Von Hermann J. Klein. Pp. 351. (Braunschweig, — 
1871. London: William and Norgate.) : 
Theoretische Astronomie. Von Dr. W. Klinkerfues, - 
Erste Abtheilung. Pp. 256. (Ditto, ditto.) f 
(London : 
part of a general description of the universe, and is de- 
voted to the solar system: another part will be given to i 
the fixed stars. The aim of the author is to afford a 
complete account of his subject, including the latest re- 
searches, which shall be at the same time thoroughly — 
scientific, while it will not be beyond the comprehension 
of those who are possessed of only an elementary know- 
ledge of astronomy, or more properly perhaps uranc- — 
graphy. The first forty-nine pages contain a description 
of the sun; the next five are given to the zodiac. Then i 

finally we have a full and very interesting account of | 
comets and meteorites. | 
Turning to the chapter on the sun, we find, after y 
general introduction, methods for calculating the distance _ 
between the centre of the sun and that of the earth. | 
After this we have an account of the “spots,” accompanied | 
with tables of their numbers in different years, and their 
connection with the movements of the magnetic needle. | 
The labours of Herschel, Airy, Lockyer, Huggins, and | 
others are largely quoted, and the author begs any ob- 

