844 Rev. 0. Fisher, On the hypothesis of a [May 18, 



This work is done by the moon upon the whole mass of water, 

 while she traverses the interval AQ. 



Hence the work clone while she makes a complete revolution 

 will be given by putting a>t = 2ir, and it will be 



ffia aco \ 2 ha 



p \jM=gh) T 2lr ' 



This work will accumulate once every lunar day. 



To obtain the corresponding rise of temperature, we know that 

 a weight m raised through s feet is equivalent to heat sufficient to 

 warm m pounds of water through s/772 degrees Fah. ; so that to 

 find the rise of temperature produced by the work W upon a mass 

 m of water we have 



W = mgs, 



and the equivalent rise of temperature in the water will be 



Wmg 



In the present instance 



m — plirha, 



and therefore the rise of temperature in the water in a lunar day 

 will be 



/fia aw \ 2 1 



V "2" aV - gh) 2#772 " 



We know that 



Ma? _ _1 



ED 3 ~ 18-2 x 10 6 



Hence ^ = ti8^T0^- 



And « = 0-000072924 radian, 



a = 3959 miles, 



h = 4 miles, 



g — 32 feet per second. 

 Reducing to feet, the rise of temperature in the water of the 

 equatorial canal in degrees Fah. comes out about 



0-000006° Fah. 

 in one year, or 6° in a million years. 



We see then that under the present circumstances a very 

 small portion of the heat generated about the earth in this manner 

 would be taken up by the ocean, and radiated into space, irre- 

 spective of the friction of the water. But Darwin informs us 



* Thomson and Tait, 2nd Ed. p. 383. 



