ATOMIC THEORY. 393 



Kendal, directing it chiefly to Meteorology a subject which 

 engaged much of his attention through life. The first entry 

 in his Meteorological Journal is of March 24, 1787, and 

 records a remarkable Aurora Borealis on the evening of that 

 day. Perchance from this very cause the phenomenon of 

 the aurora (even now imperfectly explained) continued ever 

 after to be a favourite topic with him. He made in the 

 beginning his own barometer and thermometer ; and used as 

 an hygrometer some six yards of whipcord, suspended from 

 a nail and stretched by a weight, with a scale attached to it. 

 This rudeness of his instruments was not limited to early 

 life. Even in the experiments which led to his great disco- 

 veries, his apparatus was grievously deficient in those refine- 

 ments which Chemistry now requires and has fully obtained. 

 His laboratory, which we once visited, might well in its 

 slovenly arrangements provoke a smile from the modern 

 adept in analysis. There was a sort of obstinacy in Dalton's 

 mind on this subject ; derived in part from the independence 

 of his own early labours in part also from an original 

 pertinacity of his nature. But some compensation was found 

 for this defect in his clear perception of the objects sought 

 for, and in that patient repetition of experiments and obser- 

 vations which reconciles discordant results, and gives certainty 

 to the conclusions obtained. The Method of Averages, even 

 where not recognised as such, involves a principle prolific of 

 truth ; and Dalton largely availed himself of it in his labours. 

 In May 1792, he first visited London, of which he says in 

 a letter to his brother, c lt is a most surprising place, and 

 well worth one's while to see once; but the most disagreeable 

 place on earth for one of a contemplative turn to reside in 

 constantly.' A longer knowledge might, perhaps, have told 

 him that a man may be alone in a multitude ; and that the 

 greatest works of contemplation as well as of practical ac- 

 tivity have emerged from amidst the din and bustle of this 





