KC Y The four-digit numbers in the column on lh« left give the lotilude and longitude of the 

 ^ ' lOulheatt corner of eoeh one degree-quodrongle. Eoch one-degree quadrangle it divided 

 into 30-(ninule quadronglei, numbered oi m the diogrom to the right. The columni of these table* 

 give: A- minimum temperature, B- moximum lemperolure, C- number of years, D - number of doyt. 



DEPTH ZONE 



23 



