CHAP. III. WOEKSHOP, AND COLLEGE. 125 



and taking an especial interest in the invention of the 

 thrashing-machine, which Meikle was at that time em- 

 ployed in bringing to completion. He was also entrusted 

 to superintend the repairs of corn-mills in cases where 

 Meikle could not attend to them himself; and he was 

 sent, on several occasions, to erect machinery at a 

 considerable distance from Prestonkirk. Rennie thus 

 gained much valuable experience, at the same time that 

 he acquired confidence in his own powers ; and before 

 the end of a year he began to undertake millwork on 

 his own account. His brother George was already well 

 known as a clever farmer, and this connection helped 

 the young millwright to as much employment in his 

 own neighbourhood as he desired. Meikle was also 

 ready to recommend him in cases where he could not 

 accept the engagements offered in distant counties ; 

 and hence, as early as 1780, when Rennie was only 

 nineteen years of age, we find him employed in fitting 

 up the new mills at Invergowrie, near Dundee. He 

 designed the machinery as well as the buildings for its 

 reception, and superintended them to their completion. 

 His next work was to prepare an estimate and design 

 for the repairs of Mr. Aitcheson's flour-mills at Bon- 

 nington, near Edinburgh. Here he employed cast iron 

 pinions, instead of the wooden trundles formerly used : 

 one of the first attempts made to introduce iron into 

 this portion of the machinery of mills. 



These, his first essays in design, were considered very 

 successful, and they brought him both fame and emolu- 

 ment. Business flowed in upon him, and before the end 

 of his nineteenth year he had as much employment 

 as he could comfortably get through. But he had no 

 intention of confining himself to the business of a country 

 millwright, however extensive, aiming at a higher 

 professional position and a still wider field of work. 

 Desirous, therefore, of advancing himself in scientific 

 culture and prosecuting the studies in mechanical philo- 



