MANUAL OF TIDE OBSERVATIONS 



21 



The subsidiary axle (30, fig. 13) on the opposite side of the drum is 

 attached to one end of the counterpoise spring and does not turn with 

 the drum. 



FiGUKE 12. — Portable automatic tide gage (left side). 



48. Counterpoise spring. — The counterpoise spring enclosed in the 

 float wire drum operates against the weight of the float and takes up 

 the slack in the float wire as the tide rises. One end of the spring is 

 fastened to the inside of the drum and the other end is attached to 

 the subsidiary axle (30, fig. 13). The latter is held fixed by a ratchet 



