CAH^ADIA^ FISHERIES EXPEDITION, lOl-i-lo 



269 



Fig. 50 shows isobars, isosteres, and solenoids in section IX. The isobars have 

 been drawn for each ten metres depth, and the isosteres, for each tenth unit of v. In 

 fig. 50, th?n, each square contains 100 cgs. solenoids. 



If now, in the isosteric sectons I-XX, plates VIII and IX we work out in a 

 similar manner the isobars for each 1 metres depth, we obtain a good view of the 

 distribution of the solenoids and their number throughout the entire area of investiga- 

 tion. Where the isosters have been drawn for each tenth unit of v„ each square will 

 contain 100 solenoids, but in the upper parts of the section, where they are taken for 

 each fiftieth unit of i\, there will be 500 solenoids to the square. It should hardly be 

 necessary, however, to draw up in practice a linear system so simple as that of the 

 isobars for each 10-metre depth; this may easily be imagined. On so doing, we obtain 



Fi^. 51. — Solenoids in section IX. 



from the isosteric sections I-XX, an immediate idea as to the position of the sole- 

 noids and their numerical values during spring and summer in the Canadian waters. 



Another good way of showing the number and distribution of the solenoids is as 

 follows: After drawing up the isobars, and isosteres, the ix»ints of intersection between 

 them are marked out. and both line systems then erased. This gives a system of points, 

 each representing 100 solenoids. By counting the points, and multiplying their 

 number by 100, we obtain the number of solenoids {vide fig. 51). 



Each solenoid lies between, and is bounded by two adjacent isobar nurfaces. Its 

 course is thus pefectly horiz()ntal, and its vertical extent amounts to exactly one 



