518 POPULAR SCIENCE MONTHLY. 



for the United States Geological Survey, but cheaper and simpler in- 

 struments can be made to serve almost as well. This instrument is best 

 carried in a leather box worn upon the belt. The aneroid, if used, is 

 carried in a leather case slung from the shoulder and passed under the 

 belt so as to be shaken as little as possible. The hammer is most con- 

 veniently carried upon the person by slipping the handle through the 

 belt, a 'pick' or prospector's form being specially secure in this posi- 

 tion because of its long head. When riding the hammer is slipped 

 under a strap on the side of the carrying frame of the rock bag. 



Where observations must be frequently taken, as in detailed areal 

 mapping, considerable time may be lost in finding a suitable support 

 against which to rest the wheel. Bicycle manufacturers should be able 

 to devise a light and simple support which can be carried with the wheel 

 and quickly adjusted. In a region adapted to bicycle work, such as 

 much of the Piedmont Plateau and the Coastal Plain of the eastern 

 United States, as well as large areas in Europe, it is believed that a 

 bicycle outfit such as is here described makes it possible to reduce 

 greatly the expense and to divide by at least one-half the time necessary 

 for mapping over that required if older methods of locomotion and 

 transportation are employed. The inertia of long-established practise 

 is, however, considerable, and geologists have been somewhat slow to 

 adopt the newer methods. The small expense of such an equipment and 

 the accessibility of the beautiful government maps make it possible for 

 private and essentially amateur geologists, with the advantages of only a 

 brief geological training and a moderate amount of experience, to col- 

 lect valuable data within the area surrounding their homes, especially if 

 these chance to be in a thickly settled part of the country. 



