ON A NEW CURRENT-METER. 175 



arrows issuing from the centre of the dial. When, as occa- 

 sionally happened^, the point of the pendulum swung right out 

 to the protecting barrier (displacement = 11 cm.), only a certain 

 lower limit for the velocity of the current can be calculated. In 

 such cases the small circles are placed in accordance with this 

 lower limit for the velocity of the current, but are continued with 

 a short arrow pointing radially outwards. 



On several dials, observations from different depths are 

 brought together, and are separated from one another by free- 

 hand lines. In the same way, observations taken at the same 

 depth, but at different times, are sometimes separated from one 

 another. 



I will take as an example of this graphical representation the 

 dial, fig. 7, PI. XVIII, which contains the following currents: 



N >4-2 ^^; NE. by N. . . 2-9— ; E. by S. 3-4 — ' 



sec. •' sec. -^ sec. 



SE. by S. > 4-2 „ S. by E. . . . 2-9 „ SW.. . . 1-9 „ 



NW. by N. 1-8 „ NW. by N. > 4-2 „ NNW. . 3-7 „ 



As the result of these observations can have no significance 

 but as slight illustrations, it is not necessary here to give the 

 tables. Some of these, however, are included as examples, and I 

 have selected those that are most desirable for the completion 

 of the graphical representation. 



I shall now proceed to the account of the observations in 

 so far as they may be of interest. 



The first experiments were made in the deeper water-strata, 

 and these gave negative results. Remarkable changes were ob- 

 served in the currents, sometimes with the time, and sometimes 

 with the varying depth; but on closer consideration, it appeared 

 that there was no conformity to any law in the changes. Nor 



The easily manipulated additional weight of 612 gr. was not made at 

 that time, and the sensitiveness was diminished by wrapping the sli- 

 ding weight in sheet-lead. 



