On reducing the Lunar Distance. 271 



manner Mr. Russell has supposed ; and I leave it to the philo- 

 sophers to make their choice between the two hypotheses. 

 I am, gentlemen, 



Your most obedient servant, 

 Bath, August 2, 1822. Walter Forman, 



P.S. — I cannot take leave of this subject without pointing 

 out to the notice of your readers a most exti'aordinary feature 

 in Mr. Russell's mode of arguing (if I may be allowed that 

 expression), which is certainly unique in the annals of philoso- 

 phy. Mr. Russell denies my hj'pothesis, and proposes an- 

 other ; but he does not think it necessary either to prove that 

 his own is true, or that mine is false. He asserts that the 

 tides are raised " by the superior gravity of those waters that 

 constitute the ebb;" but where are his proofs ? He does not 

 explam in what way the downward pressure of the waters on 

 one part of the globe can cause the waters on another part to 

 rise up ; and yet he expects me to combat a position, when it 

 is morally impossible that I can understand what he means. 



As however he has thought proper to throw the burden 

 upon my shoulders, I am ready to undertake it; because, 

 though I cannot be expected to combat an argument before 

 it is put, it is easy to show that his hypothesis cannot possi- 

 bly be true. Mr. Russell, I suppose, is so much of a philoso- 

 pher as to know that, whenever it is low water in any place 

 (let him choose where he will), the tides are rising on one side 

 of it and ebbing on the other; and, if the " superior gravity" 

 of the water in this place cannot prevent the waters from ebbing 

 on one side, it is not very philosophical to suppose that it can 

 lift the waters on the other. 



LII. On reducing theL/unar Distance. 2?v/ Henry MeiklEj^s^-.* 

 To the Editors of the PhilosopJiical Magazine and Journal. 



Gentlemen, — In my communication which you had the 

 goodness to insert in the Philoso))hical Magazine tor Septem- 

 ber last, a method was proposed for constructing a general 

 plate for reducing the lunar distance; and its loading feature, 

 so far as relates to parallax, was shown to consist in the ar- 

 rangement of three parallel straight lines in such a manner 

 that when two of them served ibr the altitudes, the effect of 

 parallax on the distance might by help of a ruler be read off' 

 irom the third. The same general principle, it was also re- 

 marked, admitted of several forms of construction ; and since 



* Conununicatcil Ity ilic Autlior. 



that 



