of the United States Geological Survey. 97 
Puysicat ResEarcueEs. 
There is a physical laboratory in the Survey, with a small 
corps of men engaged in certain physical researches of prime 
importance to geologic philosophy. ese researches are ex- 
perimental, and relate to the effect of temperatures, pressures, 
ete., on rocks. This laboratory is under the charge of the 
Chief Chemist. 
LirHowoey. 
There is a lithologic laboratory in the Survey, with a large 
corps of lithologists engaged in the microscopic study of rocks. 
These lithologists are field geologists, who examine the collec- 
tions made by themselves. 
STATISTICS. 
There is in the Survey a division of mining statistics, with a 
large corps of men engaged in statistic work, the results of 
which are published in an annual report entitled ‘ Mineral 
Resources.” Mr. Albert Williams, Jr., is the Chief Statistician 
of the Survey. 
ILLUSTRATIONS. 
ee illustrations for paleontologic and geologic reports. 
will not hereafter be used for embellishment, but will be strictly 
confined to the illustration of the text and the presentation of 
such facts as can be best exhibited by figures and diagrams. 
All illustrations will, as far as possible, be produced by relief 
methods, such as wood-engraving, photo-engraving, ete. 
es. . 
Mm extinct life of the globe. Fossils are indices of geological 
vrmations, and must be grouped by formations to subserve 
ue purpose of geologists. Fossils also have their biologic 
relations, and should be studied and arranged in biologic 
Soups. Under the plan adopted by the Survey, the illustra- 
