COMPILATION BOOK 41? 



vened, are recorded upon one or two pages, and are available for use in 

 drawing a map. 



In the office, therefore, and with a fresh map ruled in squares, the 

 geologist begins with 1, 1.1, and plots in the geology square by square- 

 Having a series of empty drawers at hand, the specimens are assembled 

 as the work progresses, and grouped by narrow localities in an easily 

 intelligible way. Should he desire to refer to the original note book and 

 field map, he does so instantly. If, moreover, one merely turns the 

 leaves of a compilation book, it is possible to note by the blank, or 

 sparsely written pages, where observations fail or are few. Revision or 

 amplification follow, if necessary, as a matter of course. Should the 

 observations be sufficiently detailed, they are available for sections at 

 any points and in any direction. It is also advantageous to select a 

 compilation book with sufficiently abundant pages, so that at the back 

 petrographical or other office notes may also be included, and every- 

 thing be thus kept together. For convenience of reference a fresh map 

 is ruled, folded, and fastened in the compilation book, the field maps 

 being left in the note book. Finally, from the first rough map the fin- 

 ished one, which is to go with the final report, may be drawn with col- 

 ored inks and a right line pen. 



Where large classes of rather numerous squads of two each are taught 

 in the field, the compilation book can be passed from squad to squad, 

 each pair writing in their notes. Finally, the record being complete, 

 each squad can use the compilation book in preparing a final report and 

 drawing a map of the whole district. With a party of ten or fifteen pairs 

 located in a quadrangle which has been mapped on the scale of -g-g-.Voir ano ^ 

 which is suitably provided with means of transportation, within a week 

 or ten days and within the limits of skill of younger workers, the whole 

 area will be overrun in the greatest detail and almost every outcrop duly 

 mapped and recorded. Areas are assigned square by square, reported 

 on systematically to the instructor in the evening, and colored in on a 

 compilation map. The students see the results gradually assuming 

 definite shape, and great interest is usually aroused in the final result. 

 When such compilation books are kept on file in an institution or placed 

 with a state geologist, they would be of much permanent value. 



Principles on which the System is Based 



The above system is based on the principle of locality for the orderly 

 entry of observations. Reflection on the subject by any experienced 

 geologist will soon develop three possibilities : First, one may not com- 

 pile at all, depending on the memory as a guide to the notes distributed 

 through several field books. The field books may be esteemed of purely 



