740 
class and was built in 1888. An interesting 
fact with regard to sedimentation in this reser- 
voir is that during the twelve years of its use 
the bed of accumulated silt in the deepest 
part (some 90 ft.) was only 8 ft. in thick- 
ness. This isin great contrast with the rapid 
silting of Lake Macdonald, the reservoir created 
by the Austin dam of Texas, whose design and 
construction, and also final failure in April, 
1900, are described by Mr. Schuyler. 
Conerete dams are next taken up, including 
the structure of that type built for the Hydrau- 
lic Laboratory of Cornell University ; in con- 
nection with which an account is given of the 
device adopted for ‘concentrating the con- 
traction due to temperature changes in the 
concrete to a central point of weakness.’ The 
resulting fissure was filled up in cold weather 
and continuity thus secured. 
In the chapter on earthen dams mention is 
made of the ancient ‘tanks’ or storage basins, 
of Ceylon, one of which was closed in by an 
embankment 11 miles in: length and 200 feet 
high; also of several in India. The other 
earthen dams mentioned are in Colorado and 
California, one of them (5.5 miles in length). 
serving to close in the Buena Vista Lake Reser- 
voir, which has great extent (25,000 acres) but 
is only about 7 feet deep. Asa result of this, 
the annual loss of water by evaporation is esti- 
mated at 70 per cent. of its capacity. How- 
ever, when the evaporation is most active, the 
loss is made good continuously by the influx 
from the river. 
The Ash Fork steel dam in Arizona, described 
on p. 222, was erected in 1897 and is an unusual 
construction, consisting of a number of ver- 
tical steel frames or trusses, connected or 
“bridged over’ at the upper side by curved 
plates of steel which form a continuous and 
water-tight covering. The structure is 33 feet 
high, 184 ft. long, and cost $45,000. 
Natural reservoirs are next mentioned ; 7. e., 
ready-made reservoirs or depressions, waiting 
only for water to be turned into them from 
neighboring streams of sufficient elevation and 
for suitable provision for its regulated escape. 
The last chapter, on ‘ Projected Reservoirs,’ 
is of considerable length and full of detail, 
treating of many irrigation surveys and projects 
SCIENCE. 
[N. S. Vou. XIII. No. 332. 
for impounding water, throughout the Western 
States and Territories. Several of the struc- 
tures mentioned are already in process of con- 
struction. An appendix of various tables made 
for the U. S, Geological Survey, and contoured 
maps of reservoir systems, complete the work. 
A very commendable feature of Mr. Schuy- 
ler’s book, and one that will be appreciated by 
civil engineers, is the information given as to 
the cost of many of the dams and other struc- 
tures described in the work. 
I. P. CuurcH. 
Annual Reports of the War Department: Report 
of the Chief of Ordnance. Washington, Govt. 
Print. 1900. 8vo. Pp. 474. Numerous 
appendices and plates. 
The reports of the War Department always 
contain much of interest to the general reader 
and to the thoughtful citizen, apart from their 
purely technical matter, as, for example, the 
accounts of work performed under the River 
and Harbor Bill. Those of the Chief of Ord- 
nance are particularly interesting to the student 
of metallurgy and to the engineer as giving 
much valuable information regarding materials, 
Occasionally a side-light is thrown upon inter- 
esting phases of governmental and official ad- 
ministration ; as where the report of the chief 
of a bureau permits the reader to see the hand 
of the politician in the determination of the lo- 
cation of important locks, in river improvements 
in the West and the reason for the displace- 
ment of a worthy and capable officer insisting 
upon correct business methods, or where, as in 
the report before us, the official documents re- 
veal the fact that a Committee of Congress, 
composed mainly if not entirely of non-experts, 
or amateurs at best, decides to ‘try an experi- 
ment’ with Government funds, to the extent 
of many thousands of dollars, directly against 
the expressed opinion of the official expert ad- 
visers of the Department and of Congress, or 
where official and expert authorities are per- 
mitted to be accused of refusing to permit the 
civilian expert reasonable opportunity to dis- 
play his talent, and the charge is left without 
complete and decisive investigation and report. 
Amateurism is not altogether a monopoly with 
departments. 
