THE CONQUEST OF THE ZONES 



ship, for the sake of dryness, where, however, it was 

 subjected to a great deal of joggling, which led to a con- 

 siderably greater irregularity of action; but even so its 

 variation on reaching British shores was such as to cause 

 a maximum miscalculation of considerably less than 

 thirty nautical miles. 



Although Harrison seemed clearly enough to have 

 won the prize, there were influences at work that inter- 

 fered for a time with full recognition of his accomplish- 

 ment. Presently he received half the sum, however, 

 and ultimately, after having divulged the secret of his 

 compensating balance and proved that he could make 

 other watches of corresponding accuracy, he received 

 the full award. 



Minor improvements have naturally been made in 

 the watch since that time, but the essential problem 

 of making a really reliable portable timepiece was 

 solved by the compensating balance-wheel of Harri- 

 son. The ship^s chronometer of to-day is merely a 

 large watch, with an escapement of particular con- 

 struction, mounted on gimbals so that it will maintain 

 a practically horizontal position. 



Modem ships are ordinarily provided with at least 

 three of these time-keepers in order that each may 

 be compared with the others, and a more accurate de- 

 termination of the time made than would be possible 

 from observation of a single instrument; inasmuch as 

 no absolutely accurate time-keeper has ever been con- 

 structed. Two chronometers would obviously be not 

 much better than one, since there would be no guide 

 as to whether any variation between them had been 



[27] 



