The present is the second of the series of reports on the collection of deep-well samples, the first of which, covering the period from the beginning of the work July 1, 1904, to December 31, 1904, was published as Bulletin No. 264. This report presents the records of a large number of wells from which more or less complete sets of samples have been secured and placed on file at the Survey, and. also many additional records not represented by samples.
The work has been conducted by the eastern section, division of hydrology, the expense being shared with the western section of hydrology and the geologic branch. The writer has continued in charge of the investigations and has been assisted by Messrs. E. F. Lines and Samuel Sanford. The burden of executive details has fallen mainly on Mr. Sanford since his assignment to the work on its relinquishment by Mr. Lines April 1. The methods followed are in most particulars those formulated by Mr. A. C. Veatch on the inauguration of the work in 1904, but to Mr. Sanford is due the credit for materially increasing the usefulness of the work to the driller, especially in furnishing geologic information.
