on the Theory of the Tides. 337 



the ebb ; for take away the ball that is not influenced by the 

 magnet, and the other immediately sinks ; take away the ebb, 

 and the flow immediately subsides. 



As Captain Forman has manifested some uneasiness at my 

 not further noticing his hypothesis, I shall select, as an ex- 

 traordinary specimen of " philosophical arguing," that part of 

 liis hypothesis where he says, " We have only to take a hand- 

 ful of water out of the ocean, at the time of the rising of the 

 tides, to be convinced that the expansion of the water is the 

 immediate cause of the phaenomenon ; because, if the waters 

 were pulled upwards by the power of the moon's attraction, 

 and not pushed upwards by the expansion of the particles be- 

 low, this water would not fall back to the earth, until the in- 

 fluence of the moon's attraction had gone off." This is, in- 

 deed, a mode of arguing which ought to be considered 

 " uniqne in the annals of philosophy." Here is Captain For- 

 man endeavouring to convince " eveiy astronomer and every 

 philosophei'," that because the moon is not capable of sustain- 

 ing a handful of water in the atmosphere, it has no power 

 of elevating it whatever ; and yet in another place he attempts 

 to inform them how much the power of the moon is capable 

 of diminishing its specific gravity. 



Captain Forman gives it as his opinion, that the attractive 

 power of the moon is to that of the earth as one to five him- 

 dred: now gi'anting that to be the case, which let us admit 

 for argument sake, I say 500 ounces of water in the absence 

 of the moon would in her presence weigh only 499. It is the 

 same with a handful of water ; the moon attracts it in one di- 

 rection with a power e(|ual to 1, and the earth attracts it in 

 another direction with a power equal to 500 ; the difference 

 of these attractive j^owers at the same time, philosophers agree 

 in calling the water's gravity ; and to suspend it in the atmo- 

 sphere requires that the attractive power of the moon should 

 be equal to the attractive power of the earth. I am surprised 

 that Captain Forman, widi all his precision and accuracy, 

 should not be able to discover a difference between the whole 

 and a part. 



The ease with which Captain Forman accounts for the tide 

 on the opposite side to the moon, is very remarkable. He 

 simply imagines a repelling jiowur, which I dely him to prove 

 the existence of, and the work is done. 



If Cajitain Forman's imaginary repulsion should by In's or- 

 der be brought into existence, I promise liim we shall very 

 soon have no moon to argue about; as in that case (similar 

 tides being elevated on opposite sides) attraction and re- 

 pulsion nmst be equal, and therefore amoimt to nothing; the 



Vol. fiO. No. 295. Nov. 1822. U u nioon 



