impossible for me to use any of the printing appropriation for a publication that is not directly connected with our current work.
With this much by way of explanation the present writer feels that no apologies are necessary. The compilation has been carried on at odd times, the manuscript in some instances lying a full year without being touched. Naturally, much desired information is wholly out of reach. The leading participants in these surveys have for the most part gone over to the majority, and the written and published results are lacking in many interesting particulars. Undoubtedly a search through State records would have brought to light more data regarding expenditures, but no funds have been available for the purpose, and the utility of greater detail is perhaps questionable. It has been the writer's custom, in all cases where it was necessary or seemed desirable, to send the manuscript to those now in charge of surveys in the individual States for such information as was available. He takes this opportunity to acknowledge his indebtedness and express his thanks for the aid thus afforded.
SUPPLEMENTAL NOTE.-It was the original intention to bring this history down to a date not later than 1885. In but few instances has this limit been passed. Any seeming desirability of so doing has been anticipated by the publication of Bulletin 465 of the United States Geological Survey in 1911.