462 
As the chief authority on the iron-bear- 
ing formations of the Upper Peninsula, 
Brooks was asked in 1869 to take charge of 
the Economic State Geological Survey of 
that district, and he accepted on condition 
that he should be allowed to secure all the 
private aid possible. The necessity for this 
provision is apparent when it is understood 
that during four years the State paid toward 
the work but $9,000, while he spent $2,000 
of his own means and received no pay him- 
self. The results of his work are embodied 
in Volumes II. and III. of the Michigan 
State Geological Survey. His reports are 
direct in style, simple in treatment and 
extremely practical in substance. They 
are models of excellence as economic geo- 
logic reports. The most original chapters, 
and those which still possess most practical 
value, relate to the principles of mine man- 
agement and of magnetic observations in 
prospecting for iron ores. For many years 
the chapters on geology were standards of 
reference, and they have been replaced only 
by most elaborate studies, based largely 
on Brooks’ work and carried out with the 
most refined methods of modern geology. 
Says Van Hise, Brooks’ successor: ‘“‘ Not- 
withstanding the immense advantage which 
it has been to have Brooks’ work as a foun- 
dation, it has taken many years of labor 
fairly to complete the structural story to 
which Brooks contributed important chap- 
ters. Only those who have labored in the 
Lake Superior region and who understand 
its peculiar difficulties can give Brooks 
credit for the remarkable work hedid. His 
geological work is my ideal of what should 
be done in a new region of complex ge- 
ology.” 
In 1873 Major Brooks’ health gave out 
under the stress of overwork to which he 
drove himself. He sought relief abroad, 
and resided in London and Dresden while 
completing his State reports. He became 
a Fellow of the Geological Society of Lon- 
SCIENCE. 
[N. S. Von. XIII.. No. 325. 
don and Corresponding member of the Geo- 
logical Society of Edinburgh. Returned to 
this country in 1876, he resided at Monroe 
and at Newburg, N. Y., and after 1883, 
during the winters, at Bainbridge, Ga.., liv- 
ing the life of a country gentleman and 
farmer. His interest in science and engi- 
neering practice never abated, and he was 
always ready with wise counsel, even 
though strength failed him for action. 
Major Brooks was characterized by in- 
tense energy, which exhausted his physique 
before he reached middle age; by original- 
ity, which combined with common sense 
made him a most efficient man of affairs; 
by keen powers of observation and deduc- 
tion, which he applied untiringly to scien- 
tific research; by geniality and affection, 
generosity, truthfulness and loyalty to prin- 
ciple, which made him beloved and stamped 
him as a man whose memory will be hon- 
ored and revered. 
BaiLEyY WILLIs. 
U. S. GEOLOGICAL SURVEY. 
SCIENTIFIC BOOKS. 
THE APPRECIATION OF NON-EUCLIDEAN 
GEOMETRY. 
Histoire des Mathématiques. Par JACQUES BOYER. 
Paris, Carré et Naud. 1900. 8vo. Pp. xi 
+260. Price, 5 frances. 
Geometry: Ancient and Modern. By Professor 
Epwin S. Crawiey. Popular Science 
Monthly (January). 1901. Pp. 257-266. 
Non-Euclidean Geometry. By Professor HENRY 
PARKER MANNING. Boston, Ginn and Com- 
pany. 1901. 8vo. Pp. vi-+ 95. 
The last section of Boyer’s attractive book is 
headed ‘Géométrie Euclidienne et Géométries 
non-HKuclidiennes.’ He says, p. 240, ‘‘ The last 
quarter of the nineteenth century witnessed the 
building up of interesting theories.’’ The next 
page continues: ‘‘But beyond contradiction 
the most original researches of this period per- 
tain to the non-Euclidean geometries, and it is 
by them that we will terminate this incomplete 
exposition of contemporary science.’’? The 
brief account which follows (less than five 
