NO. 1 HARTMAN: QUANTITATIVE SURVEY 3 



A map of the area (Chart 1) has been marked off by intersecting 

 h'nes two minutes of latitude and longitude apart, choosing all even 

 minutes of each, or about every two miles. It is at once obvious that a 

 small sample covering approximately two square feet of surface and 

 with a volume of about two or three cubic feet, is very meager to repre- 

 sent a seabottom that measures nearly four square miles in surface area. 

 Furthermore, it was soon found that even though a uniform sampling 

 device was employed, few of the samples measured as much as two cubic 

 feet, especially when taken from the shallower waters of the continental 

 shelf, where measured samples were as small as a tenth of a cubic foot. 

 Others, from soft oozy muds in great depths, measured well over three 

 cubic feet. It was found also that the degree of penetration of the grab 

 varied in different kinds of bottoms ; these varied from the finest muds 

 to compact sandy or shelly gravels to clay. In addition, the incomplete 

 closure of the jaws of the grab may have caused the loss of contents on 

 the way to the surface. Some of these difficulties have been met through 

 improvements in techniques as the sampling continued. 



Although the studies are not complete, it seems worthwhile to describe 

 the methods that have been used, and to indicate preliminary results 

 which are remarkable for their qualitative and quantitative relations. 



