224- Capt. For man on Dr. Young's and La Phae's 



cific gravity of A to be somewhat more than tliat of B. Now, if 

 tlie moon stood still, there would necessarily be a fall of the 

 waters at A and a rise at B, until, in consequence of the in- 

 creased quantity of the lighter particles and the diminution of 

 the heavier ones, the weight of the two portions became exactly 

 equal. But, in consequence of the moon's continual motion, 

 tlie specific gravity of all the particles of water is continually 

 chano-ing, and consequently, the moment the particles at A be- 

 gin to press upon B, the weight of B becomes equal to the 

 weight that A possessed at the time the pressure commenced; 

 and though the weight of A, for some time at least, is continu- 

 ally increasing, yet, as the weight of B increases in the same 

 proportion, the resistance on the one side will always be equal 

 to the pressure on the other. Suppose a person to be continu- 

 ally throwing weights into one scale in order to lift up the 

 other, but that the weight of the opposite scale (no matter by 

 •what means) constantly increased in exact proportion with the 

 power that was employed to lift it : does it not necessarily fol- 

 low that the two scales, under these circumstances, must al- 

 ways preserve the same equipoise ? And, by the same rule, so 

 long as the moon continues to change its place, the resistance 

 of the particles on the one side will always be equal to the 

 pressure on the other. Fortunately, however, this fact does 

 not rest upon mere opinion. There is a case almost precisely 

 analogous, in which a much greater disproportion of pressure 

 does not produce any sensible alteration in the relative position 

 of the waters; and if the effect is not produced in this instance, 

 we have no right to conclude that it can be in the other. The 

 eardi moves in its orbit with a velocity equal to 68,000 miles 

 an hour ; and while it is pressing upon the waters before it 

 with this amazing force, it is simply dragging the waters be- 

 Iiind it by the power of its attraction. Now, if the same parts 

 of the earth's circumference (supposing them to be water) were 

 always before and behind the earth's track, there would no 

 doubt be a fall of the waters before and a rise behind, until the 

 greater pressure of the waters before were counterpoised by the 

 greater quantity of the waters behind. What is the reason, 

 then, that this extraordinary pressure does not produce a rise 

 and tall of the waters, but because the effect is entirely counter- 

 acted by the earth's revolving on its axis ? Before those waters 

 which are immediately before the earth's track can produce any 

 effect by pressure upon their neighbours, they are removed to 

 the very situation their neighbours occujiied the moment before, 

 and are prevented from falling by the greature pressure of those 

 particles which have just taken their places. MMiether this rea- 

 soning be good or not, it is clear that this extraprdinaiT pres- 

 sure 



