416 J. F. KEMP — GEOLOGICAL BOOK-KEEPING 



rangles are situated farther south, the east- and- west dimensions widen 

 appreciably, and for those farther north they become more narrow. 

 With the increasing width the ninth of the fourth dimension becomes 

 larger and it may be desirable to add a fifth ninth. This, however, goes 

 automatically, and it is slight trouble to use the additional digit. The 

 variability of the east-and-west spaces makes it necessary to refer to the 

 scale of each sheet in order to use the subdivisions as scales of actual dis- 

 tance, but should the method receive any extended adoption it would 

 be a great convenience to field workers if the United States Geological 

 Survey Would print upon the map for those who wished light surcharges 

 of rectangular ninths of the second dimension, the 5 minutes of longitude 

 and latitude in the scale er-Wo forming the ninth of the first dimension. 

 For surcharges of this sort a series of squares, such as a mile on a side 

 and having an invariable size, would be much less expensive and more 

 convenient than one whose size varied with every 15 minutes of latitude, 

 and therefore the writer favors the use of those a mile on a side and in 

 blocks of four. 



The Compilation Book 



For the compilation book a blank book is selected of convenient size, 

 and preferably a standard one, which can be always obtained of the 

 dealers. It is then paged in a series corresponding to the squares, 

 usually 1.1; 1.2; 1.3; 1.4; 2.1; 2.2; 2.3; 2.4; 3.1, and so on, to 87.3 

 for the first method of squares, or up to 9.9.9 for the last one. Now, 

 taking the field book day b}' day, the notes are copied into the compi- 

 lation book, each on the page corresponding to its square. At the top of 

 page 1.1 is put the observations in 1.1.1; and if 1.1.9 is first met in 

 transcribing the field notes, its record is placed at the foot. Intermediate 

 ones are interpolated at intervening points as nearly as the compiler 

 will estimate their serial location. Note books should all be numbered 

 in series and paged. Two compiled notes may then read as follows : 



1.1.7.5. B.26, 117, Gabbro-gneiss N. 70 E. 45 N. Spec. 261. Becomes 

 massive 100 paces north. Glacial scratches N. 60 E. and N. 40 E., 

 former older. Trap dike, 4 ft. wide. N. 45 W. Spec. 262. 



1.1.8.9. B.45, 23, Beekmantown 1. s. 40 ft. exposed. N. 50 W. 10 

 E. Silicious, no fossils. Glaciation ! ! N. 60 E. 



From the first we know that in this particular square, as recorded in 

 note book number 26, page 117, gabbro-gneiss occurs, with the strike and 

 dip given, and with the associated phenomena subsequently recorded. 

 The significance of the record for the next square is apparent. When 

 the field work is completed in a quadrangle or any part of it, all the 

 observations ever taken on any square, no matter if years have inter- 



