FEBRUARY 4, 1904] 
NATHIRE 
Or 
31 
of its application in the third section on kinetics, but 
special attention is devoted to harmonic motion, a 
matter of great importance to engineers engaged in 
the design of valve gears, and the investigation of the 
valve motion due to any type of gear. In the intro- 
ductory chapter to kinetics, the author discusses fully 
the difficulties due to the two systems of units adopted 
in dealing with ‘‘ mass ’’; he realises that the gravita- 
tion system, or so-called ‘‘ engineer’s system,’’ is not 
likely to be displaced in spite of the constant en- 
deavours of reformers; it is, in fact, too convenient 
and enters too constantly into the ordinary engineer’s 
everyday work to be lightly given up. He suggests 
a name for it—the gee-pound or the gee-kilogram— 
but we are afraid such names are never likely to be 
adopted generally; the present method of explaining it 
as the ‘‘ engineer ”’ unit is sufficient for all practical pur- 
poses, and the names suggested seem to us only to add 
to the existing confusion. This section is an exceedingly 
| affords a 
good one; the practical applications are well chosen, 
such as inertia of reciprocating parts in engines, | 
vibration of springs, moments of inertia of solids of 
revolution, governors, balancing of rotating bodies, 
friction of pivots, &c. 
In a series of appendices the author treats briefly of 
vectors, rates, dimensions of units and second moments 
of areas. 
student of engineering who is striving to get clear 
ideas of the fundamental principles on which so much | 
of his work is based, and will probably be adopted in 
many technical colleges as one of the standard text- 
books on mechanics. ii Ele B: 
THE GROWTH OF A FEDERAL EMPIRE. 
Geographic Influences in American History. By 
Albert Perry Brigham, A.M., F.G.S.A., Professor 
of Geology in Colgate University. Pp. xii + 366. 
(Boston, U.S.A., and London: Ginn and Co., 1903.) 
Price 6s. 
pee BRIGHAM, already known to geologists 
by a concise and clearly written text-book, here 
makes an appeal to the historian and the geographer. 
He does not start with generalisations as to the arrival 
of the first men on the American continent, or as to 
its situation between the two ends of the Old World; 
but he brings us at once to 
Columbus, of Cartier, and then of the English 
settlers, who found Spaniards south of them and 
Frenchmen to the north, and who thereupon colonised 
the central seaboard. ‘‘ America,”’ 
in this compact 
treatise, is wisely limited to the United States, with | 
so much of Canada as is inevitably mingled with their 
history. The style is direct and even vigorous; in 
Prof. Brigham’s crisp sentences there is a continual 
mental stimulus, and it would be hard to find a re- 
dundant word. We do not like the poetry that is 
quoted in the book, for the benefit of the general 
reader, half so much as the author’s own admirable 
prose. 
The rise of New York is traced to the formation 
of the Erte Canal in 1825, whereby the grain of the 
central plains was brought through the Mohawk gap 
No. 1788, VOL. 69] 
The book will be useful to the private | 
the adventures of | 
and floated down the Hudson. The Appalachians 
have long proved hard to traverse further south, the 
railways, some of them quite recent, crossing the 
range at heights of about two thousand feet. The 
story of the decay of agriculture in New England (p. 
47) throws a somewhat melancholy light on the com- 
petition between east and west. The author (p. 64) 
believes that the decay is temporary, and that much 
of the farm-land in the east will relapse into beneficial 
forests. The possibility of a balance of mutual utility 
between districts one or two thousand apart 
pleasant contrast with our tariff-bound 
Disunited States of Europe. When, however, Prof. 
Brigham asserts that North America was meant to be 
owned by one great nation, we think that he is reason- 
ing backwards from the feelings of the present day. 
A strong Spanish race might long have held the west, 
a strong French federal republic might conceivably 
have occupied the plains, and a chain of custom- 
houses might have existed in the twentieth century 
on the rim of the Alleghany plateau. We suffer daily 
in the Old World from violations of geographical pro- 
priety, which far surpass anything that would have 
arisen from such a partition of America. 
Prof. Brigham is, however, always willing to lay 
a proper stress on human enterprise and human in- 
dividuality. The eastern States became divided (p. 75) 
as much by differences of ‘‘ breeding ’’ and ancestral 
habit as by geography; and the men whose modes of 
thought allowed them to work hard with their hands 
have naturally come best out of the struggle. 
We have some suspicion that the author prefers 
Pittsburg to the blue-grass meadows of Kentucky, 
even when he pictures so charmingly (p. 102) the 
primitive backwoodsmen, brought up amid a ‘‘ stable 
environment in a remote region.’’ After all, the de- 
velopment of machinery has been the making of 
American agriculture, and it may be difficult, in such 
a country, to perceive that the growth of cities beyond 
a certain size and standard is as inimical to social 
development as is actual isolation in the fields. In 
the Old World we have so many interests, unconcerned 
with material prosperity, that we view the growth of 
Glasgow or Duluth (p. 137) with concern rather than 
exultation. There is plenty of romance, however, in 
the story of the capture of the French area on the 
Mississippi (p. 147) from its English overlords, and 
abundant cause for national fervour in the map given 
opposite p. 314, showing the progressive expansion 
of the United States. The most striking feature, 
perhaps, in this graphic epitome is the extent of the 
Louisiana territory, obtained by purchase from Spain 
in 1803, and stretching west from the Mississippi to 
the head-waters of the Missouri. 
miles 
““The West,’ says Prof. Brigham (p. 308), ‘is the 
cosmopolitan part of America. A thousand miles is 
a short excursion, and across the continent is not an 
undertaking. Men who could not change their 
horizon without homesickness did not go west; they 
are independent of distance, they are accustomed to 
looking up to find their mountains, and their children 
are born into their wide, free life.”’ 
ce 
After remarking that the Pacific coast will “in 
coming days be commercially independent of the 
