Reply to Caleb Mainspring's Observations. 105 



ments who has assumed the name of Caleb Mainspring. I 

 am afraid this writer is either some disappoisted chronometer- 

 maker, who has failed in his attempts to gain a Greenwich 

 prize, or else he is in " good sober truth" the mighty oracle 

 of such a club as that which he himself describes, held at the 

 " Tippling Philosopher in Liquorpond-street." If this latter 

 is the case, as is most probable, he should be content to con- 

 fine his nonsense within the walls of his club-room, where 

 alone it will be received as gospel : in the present case 1 ani 

 afraid he has got himself into as bad a scrape as Paddy 

 O'Rourke the Irish schoolmaster, who, not content with bear- 

 ing away the palm from the King's excise-officer in a dispu- 

 tation on the cubic contents of a whiskey-still (which he had 

 computed to the third decimal place), actually engaged in a 

 contest with the parish priest of Kildrogan, which ended in 

 poor Paddy being excommunicated. 



But to come to the point : I hereby aver that the watch 

 No. 2, in the paper referred to, is a much more perfect instru- 

 ment for the purposes of navigation than was ever yet con- 

 structed by any maker; and that No. 1, or the chronometer 

 as it is termed, only possesses that common degree of merit 

 which is to be expected from such works at the present day. 



With respect to the general merits of the rule given by the 

 late Board of Longitude I have nothing to say, as our tip- 

 pling philosopher has deferred giving us the original docu- 

 ment till some future time ; but it is certain that in the case of 

 these two watches, that rule would award the prize to an in- 

 strument which has arrived nearer perfection than any one 

 which has yet been made, in pi-eference to one of ordinary 

 merit only. 



To prove this, let us examine the rates of the two watches, 

 as given for sixty days : No. 2 has a constant mean rate, but is 

 liable to a variation, the maximum of which is 3"*8 ; No. 1 has 

 an accelerating rate, luid is also liable to a variation in that 

 acceleration of l"-2. Now the gentleman from Liquorpond- 

 street informs us, that these sixty days are feir specimens of what 

 will take place, and that the two watches may be depended 

 upon to go in this manner for twelve months. Now let us 

 suppose the two watches sent to sea on the first of the sixty 

 days for a voyage of six montiis, it is evident that at the end 

 of tiiat time, or at the end of any indefinite time, the watch 

 No. 2 will never be in error more than the daily variation 3"'8, 

 or less than one mile of longitude. It is to be hoped that by 

 wiiatever rule the merits of watches aie to be tried, our tip- 

 jjhng philosoplicr will never wish for a belter one than this lor 

 its pro))er purpose. 



On the contrary No. I, which has a constantly accelerating 

 N.S. Vol.7. No. S8. I'Vh. 1830. P rale, 



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