METHOD OF COLLECTING SAMPLES. 9 
available information is furnished the applicant. From the records 
the geologist is able in many cases to give suggestions as to type of 
well, method of drilling, etc., and to offer such encouragement as the 
facts warrant to those contemplating the sinking of deep wells. In 
return the driller is requested to furnish written records of his wells 
and samples of materials penetrated, his assistance being acknowl- 
edged in the reports on well records issued annually. 
List of drillers. — One of the first steps is to secure the names and 
addresses of competent drillers, a task of some difficulty because of 
the lack of a comprehensive drillers' directory, the nonexistence of 
any trade publication devoted to drilling, and the general absence 
of advertisements of drilling firms in engineering publications. 
Advertisements for bids, however, appear in such publications in 
case of most of the deeper water wells, and by communicating with 
owners the addresses of drillers are obtained. Some addresses are 
procured through news notes in the trade journals, especially in oil 
publications, while still others are obtained from well reports received 
from postmasters, town and county officials, and geologists in the 
field. 
Initial correspondence. — To the addresses procured from the above 
and other minor sources letters are sent calling attention to the 
nature of the system for the collection of samples and records and 
the benefits to be derived from it by the driller. With the letter is 
inclosed a sample of the bags used for shipping the samples under 
frank through the mails. When favorable replies are received, 
notebooks especially devised for the use of drillers and containing 
pertinent suggestions and simple geologic definitions are mailed, 
'together with a supply of canvas bags for mailing the individual 
samples. 
When the drillers are not at the time engaged in drilling, special 
blanks are mailed for the purpose of obtaining records of previously 
completed wells. Similar blanks are also frequently sent to well 
owners. Much data of value in determining the geologic features of 
the different regions and of economic importance from the stand- 
point of underground waters and oil or gas has been procured in this 
manner. 
Examination and filing of samples and records. — As soon as received 
at the office the samples are transferred from the bags to properly 
labeled glass bottles. Those most commonly used are approxi- 
mately 2f inches long and three-fourths of an inch in diameter, but 
glass jars measuring 3 by 1| inches are employed where the frag- 
ments are larger or where they contain fossils or pebbles. As soon 
as a set of samples is completed it may be taken from the temporary 
filing cases in which it has previously been stored and, after refer- 
ence to a geologist for examination and identification of horizons 
