384 APPENDIX CALCULATION OF THE 



hence if to 0-0234783 

 we add . . 0-2007385 



we have -f 0' 1772602 as the logarithm 



of the natural number which is to determine the law 

 of decrement. 



But the natural number corresponding to 0*1772602 

 is 1*504, and which, if we disregard the last figure, 

 4, may obviously be expressed by the fraction 



15 3 



- ~ , a result similar to that which has been 



already found by means of the natural sines. 

 Fig. 362. 



Let us next require the law of an intermediary 

 decrement producing a particular modification of the 

 rhomboid belonging to class d. And let us suppose 

 that we have measured the inclination to Pand P', of 

 that plane with the letter d upon it, which rests 

 on P', see fig* p. 204. 



Let d on P be found 132 13' 

 d.. P' . . . . = 145" 57' 

 Hence 180 132 13' = 47 47', which we may call / 6 



and 180 145 57 34 3' 7 7 



/, it will be recollected is 105*5'. 



