82 LIMITS AND FLUXIONS 



Berkeley pretends to derive from them. Jurin 

 succeeds, we think, in establishing the contention 

 that there is no greater difficulty in explaining the 

 second or third fluxion, than there is in explaining 

 the first. " The second fluxion is the velocity with 

 which the first fluxion increases." Jurin confesses 

 that his statement in his first reply to Berkeley, to 

 the effect that certain errors were of "no significance 

 in practice," was intended for popular consumption, 

 for men such as one meets in London. 



103. "One of them, indeed, could make nothing 

 of what I had said about the length of a subtangent, 

 or the magnitude of the orb of the fixed stars ; but 

 was fully satisfied by the information given him by 

 one of his acquaintance to the following effect. The 

 Author of the Minute Philosopher has found out that, 

 if Sir Isaac Newton were to measure the height of 

 St. Paul's Church by Fluxions, he would be out about 

 three quarters of a hair's breadth : But yonder is one 

 Philalethes at Cambridge, who pretends that Sir 

 Isaac would not be out above the tenth part of hair's 

 breadth. Hearing this, and that two books had 

 been written in this controversy, the honest gentle- 

 man flew into a great passion, and after muttering 

 something to himself about some body's being over- 

 paid, he went on making reflections, which I don't 

 care to repeat, as not being much for your honour 

 or mine." 



104. Jurin thereupon takes up the rectangle 

 AB. The terms "moment" and " increment " 

 are involved in the discussion of it. Jurin de- 



