SEA LOG AND SOUNDING MACHINE. 251 



deep vater, where it is not possible to take them by the 

 common lead. 



This sounding machine is on the same principle as the prinsiple of ths 

 log, for it is evident, that, if the end e of the register, a, ^aclmie. 

 (Jig 1) were projected into the water, and suffered to des- 

 cend, the rotator would follow, and register the exact depth, 

 as well in a perpendicular, as in a horizontal position. 



But though the principle of the two machines is the same, 

 their construction necessarily differs considerably, as will be 

 perceived on reference to the plate. 



Fig. 2 represents the sounding machine, a is the sound- Description of 

 ing weight, containing a register, 1, 2, with two dials: the * ' 

 hand of the dial 1 makes one revolution when the weight 

 has descended twenty fathoms, the other revolves once when 

 the descent amounts to five hundred fathoms. A rotator, 6, 

 similar to that attached to the log, communicates with the 

 wheel work of the dials 1, 2, by means of the rod c, on which 

 there are three universal joints, 3, 4, and 5. This rod is 

 supported during the descent of the weight, by the drop, cZ, 

 at the end of which is a fork, 6, and a friction wheel, 7- 



When the machine is to be used, a sounding line is fiisten- Meihod oT 

 ed to the ring, e; and one of the vanes of the rotator Is slip- ""'"^ 

 ped into the spring 8 : the rotator will then be in the position 

 indicated by the dotted lines, x. The indices must be set at 

 0, and the cover or lid,y^ be shut. The machine must then 

 be projected perpendicularly into the sea. As soon as it 

 readies the surface, the resistance of the water forces the 

 dotted rotator,^, out of the spring 8, and it assumes its 

 perpendicular direction as represented by the rotator />. As 

 the machine descends, it is evident the rotator will revolve, 

 and its motion be communicated freely past the friction 

 wheel 7, and the universal joint 5, to the wheel work of the 

 dials 1, 2, and thus indicate the space passed through in fa- 

 thoms. When the machine has arrived at the bottom, the 

 rotator, as it is no longer buoyed up by the reaction of the 

 water, will fall to the bottom, quitting the fork of the drop 

 d, which will also fall from its horizontal position, and in it« 

 descent, by means of the locking rod 9, prevent the rotator 

 from revolving as the machine is drawn up. When at the 



bottom, 



