88 Britain's Heritage of Science 



an important paper entitled " Conjectures concerning the 

 cause and observations upon the phenomena of earthquakes " 

 to the Philosophical Transactions of the Royal Society, 

 and was the first to suggest that double stars were more 

 likely to be systems of physically connected bodies than 

 accidental coincidences in the directions of two stars which 

 might be at great distances one behind the other. This, as 

 will presently appear, was subsequently proved by William 

 Herschel to be the case. 



It is not surprising that astronomy has always been a 

 favourite study of men of leisure, with a scientific turn of 

 mind. As Tyndall, in one of his lectures, said, we are most 

 impressed by what is either exceptionally large or excep- 

 tionally small; and the feeling that in examining the 

 heavens, our laboratory, no longer confined to a few cubic 

 feet, extends through the universe, fascinates the human 

 mind. Added to this, useful work can be carried on in 

 astronomy with comparatively simple though sometimes 

 expensive appliances, and to the painstaking, but not 

 perhaps, mathematically inclined enthusiast, special pro- 

 blems are often ready to hand, which depend on accurate 

 registration rather than on extensive knowledge. When, 

 as not infrequently happens, the power of dealing with 

 the observations is added to the aptitude for observation, 

 the amateur can rise to the level of the professional more 

 easily than in most other subjects. 



It is impossible to say what position Jeremiah Horrocks 

 (1619-1641) might have attained had his life not been 

 cut short so early. He died at the age of twenty-two, with 

 a remarkable record to his credit. After passing through 

 Emmanuel College, Cambridge, as a sizar, he earned his 

 living as a teacher at his native place, Toxteth Park, near 

 Liverpool. Through William Crabtree, a wealthy draper 

 of Manchester, whose acquaintance he had made, he became 

 interested in astronomy, and on his advice studied the 

 works of Kepler. Having tested and corrected the tables 

 giving the positions of planets which had been published 

 by that astronomer, he formed the conclusion that a transit 

 of Venus would occur on the 24th November 1639. This 

 happened to be a Sunday, and Horrocks being at that 



