722 
NATIONAL RESEARCH COUNCIL 
able supplies of every sort, and to tabulate for prompt reference the capacity 
of all commercial workings. 
The area covered includes all of the states from Maine to Texas, with an 
intensive detailed study of certain states covering a belt from 10 to 20 miles 
back from the coast line. The work has been performed gratuitously by 
geologists familiar with the local conditions in each of the states in association 
with highway engineers representing the American Association of State High- 
way Officials, the full reports by states covering {a) the topography, climate, 
and geological conditions; {h) a digest of the active and inactive quarries, 
quarry sites, sand and gravel pits, rubble piles, and stone walls where mate- 
rials may be obtained quickly; (c) a summary of road machinery available at 
given points, and a list of engineers with their qualifications for undertaking 
road and bridge construction ; {d) and a series of maps representing this infor- 
mation cartographically. Two sets of the detailed reports for file in the 
general and departmental archives have been prepared in bound volumes and 
atlas cases for ready reference. The reports have been abstracted and con- 
ditions summarized by Military Departments and State Divisions. 
Eventually, and because of the value of the compiled data, the entire work 
will, it is hoped, be put in permanent form. 
2. Measurement of Earth Vibrations as a Means of Locating Heavy Bat- 
teries. — It was early suggested that a perfected seismographic apparatus 
might be devised which would be competent to detect and measure, by earth 
vibrations, the distance of heavy artillery discharges. The matter was 
studied carefully by the most competent seismologists, and Dr. Reid, of the 
Committee, on his trip to the war front, was specially commissioned to look 
into any actual or possible applications of this service. The service which 
it was thought ought to be rendered by seismic ranging, is now being given by 
sound ranging and airplane observation. Dr. Reid, however, a member of 
this Committee, has given successful attention to the means of correcting the 
troublesome compass variation in rapidly-moving airplanes, in which work 
he ha,s cooperated with the Committee on Physics of the Research Council. 
3. Water Supply for Camps. — This subcommittee was organized under the 
title of Camp Sites and Water Supply, in the expectation that the knowledge 
the members were competent to supply would be of service in the selec- 
tion of camp sites, with reference to quality of soil, topography and under- 
drainage, ground water and deep water distribution. In the location of the 
present camps this knowledge was only incidentally used, it being assumed 
that other agencies were adequate. 
As the military camps are now located, the subcommittee retains its organ- 
ization to meet any demands for information regarding water supply or 
other questions which may develop with the growth and further movements 
of the Army. 
4. War Minerals. — The Subcommittee on Imported Minerals, instituted 
by this Committee, has merged into an independent Committee on War 
