26 Instructions to Field Parties. 



work, and thus the long and tedious process of a complete chem- 

 ical analysis may often be avoided. 



Care in attending to these details will insure the greatest accu- 

 racy and the earliest completion of the work, so that the results 

 may be available as soon as possible, preferably before the party 

 leaves the district. 



Write all cards and tags on samples of soil in ink, as pencil rubs 

 badh^ and is sometimes illegible when received in the othce. 



Correspondence and weekly report. — All correspondence with the 

 Bureau should be addressed to the Chief of the Bureau. At least 

 once each week the head of the party should report to the Chief 

 by letter, informing him of the progress of the work, the results 

 which have been attained, describing new types of soil, and giv- 

 ing a statement of the health of members of the party. 



At the end of each week a report on card. Form 49, should be 

 filled out and returned to this office. This card report is not to 

 take the place of a weekly letter, but should be accompanied by a 

 letter giving in detail the operations of the party. The cards will 

 be filed in the office for ready reference. 



Field and office maps. — As fast as the soil maps are completed 

 copies should be sent to the Chief of the Bureau to be filed. To 

 facilitate this, two copies of the base map are fo be made. One 

 copy should be cut into sections not more than 5 by 7 inches in 

 size. As soon as the soils have been surveyed on a section an ex- 

 act copy should be made and forwarded to the office. With each 

 section should be sent a legend and a profile of each soil type. 

 On the completion of an area or sheet all field maps, with com- 

 plete legend and profile, and all notebooks, plane-table sheets, or 

 data collected are to be forwarded by registered mail. The Jield 

 copy should Ije correct in every detail when sent to the office, as 

 the copy that is sent to the printer is prepared from this or cor- 

 rected from this, and not from the office copy. Necessary changes 

 in the office copies previously forwarded will be made in this 

 office from the original field copy. The field copy will be the 

 official copy until the map is published. It should therefore be 

 as distinct and as accurate as possible. 



Directions for mapping alkali soils. — The intervals for the alkali 

 maps are to represent, respectively, 0.20, 0.40, 0.(^0, 1, and 3 per 



