FORESTRY QUARTERLY 



Vol. XII.] June, 1914. [No 2. 



LIBRARY 



DESIGN OF A RANGE FINDER. ^^^ ^^^^ 



ttOTANICAJ 



By Lincoln Crowell. uakdbn. 



Some time ago, I designed a range finder for lookout stations 

 to be constructed entirely of metal. At present the accuracy 

 and expense of such an instrument do not seem warranted. 

 Therefore I have devised another range finder, which, while 

 nnitp accurate, is nevertheless cheaolv and easilv constructed. 



ERRATA 



On page 137, volume XII read in 8th line: 

 **strap iron" for "scrap iron;" in 19th and 20th 

 lines: "minutes" for "feet." 



Upon the circumference of such a circle graduations of 30 feet 



or 15 feet can be accurately drawn. Five degree graduations are 



obtained by measuring their natural tangents along the edge of a 



circumscribed square, and by laying off the single degrees with 



dividers along the circumference of the inscribed circle. By this 



method the azimuth circle can be quickly and accurately drawn. 



^ The paper disk and alidade are covered with a heavy coat of 



rr shellac. When exposed to the weather the instrument is covered 



*~" by a box with a pitch roof. 



CO 



