PLYM AND TAMAR HUMANE SOCIETY. 85 



from which to compute heights and make scientific calculations 

 at half tide (whether springs or neaps) the surface of the water stands 

 at the above height. It is high water in Hamoaze at full or change 

 at 5h. 33m. but the highest tide happens at 7h. 10m. the least tides 

 being at llh. 49m., the greatest range of tide from low to high 

 water on the same day is 19ft. 3in., and the least only 5 feet. From 

 April to October the evening exceeds the morning tide by 8 inches, 

 but during the winter months the morning tides are higher by 8 

 inches. The most interesting result deduced from these observations 

 appears to be that the medium level of the sea is subject to changes 

 in consequence of fluctuations in the weight of the superincumbent 

 air as indicated by the barometer. Mr. Walker says these fluctu- 

 ations are perfectly consistent with philosophical reasoning and the 

 laws of equilibrium in fluids : again, the atmosphere surrounding 

 the globe may be taken as a constant quantity, and all fluctuations 

 in it as transfers of pressure from one locality to another; so that if 

 a diminution of atmospheric pressure take place over a part of the 

 ocean the water will flow in, and raise the surface until the equili- 

 brium be restored. Just as the water rises in the bore of a pump 

 as the weight of the atmosphere in it is diminished. The lecturer 

 stated that, if the mercury fall 1 inch in the barometer, the surface 

 of the sea rises about 16 inches; and if there be a rise in the baro- 

 meter the water, by the increasing pressure of the atmosphere, will 

 be lowered on an average 16 inches to 1 inch of mercury: all this 

 was explained as perfectly consistent with the laws of nature, and 

 we regret that our limits will not allow of a more detailed account 

 of the various and highly interesting topics adverted to. 



THE SPECTATOR. No. V. 

 PLYM AND TAMAR HUMANE SOCIETY. 



IT was stated, by a correspondent, in the Spectator, 

 No. I, that the objects of this society were to resusci- 

 tate persons apparently dead by drowning; and to 

 confer suitable rewards on such individuals as risked 

 their own lives in endeavouring to save those of their 

 fellow creatures. 



In proof of the necessity of such an institution, in 

 this port, it may be mentioned, that the honorary secre- 

 tary to the institution, in his second annual report, 



