Memoir of the late Mr William Blackie, 96 



the whole course of his future life. While digging in the 

 garden, he happened to turn up the bottom of a chrystal 

 tumbler ; it was concave ; and, on looking through it, he ob- 

 served that it diminished the object. He then thought 

 whether, if the glass were convex, it would have the effect of 

 magnifying the object. This he resolved to bring to the test 

 of experiment ; and immediately proceeded to grind the piece 

 of glass into a convex form. At this time, he was entirely 

 ignorant of optical science ; nevertheless, after long and hard 

 labour, by means of a common grindstone, he succeeded in 

 giving his glass the desired form ; and he polished it with 

 earth. He then found that, rough as his workmanship was, 

 the convex glass realized all his expectations. 



Delighted with his success, he now resolved to attempt the 

 construction of a telescope. With this view, he procured two 

 pieces of glass, which he formed into lenses in the same man- 

 ner as the bottom of the tumbler. He could, at first, procure 

 no better tube in which to fix his lenses than a cabbage-stalk, 

 hollowed out. One day, while he was enjoying the performance 

 of this rude instrument near Locliend, he was accosted by a 

 young man of the name of Forbes, who held in his hand a 

 properly constructed telescope, and who proposed to Blackie 

 to exchange instruments for a few minutes. Blackie shewed 

 much reluctance to allow a stranger to inspect his telescope, 

 but at last yielded to the entreaties of Mr F., who was much 

 delighted and astonished at the effect produced by means so 

 rude and simple. This interview led to the formation of a 

 friendship which continued throughout life. It was at Mr 

 Forbes's suggestion that William began to attend the lectures 

 delivered at the Leith Mechanics'* Institution, on Mathematics, 

 Chemistry, and Mechanical Philosophy, which he did in the 

 Session 1827-28. He continued to attend these lectures di- 

 ligently until 1832, acknowledging that he derived from them 

 much benefit. He also actively availed himself of the use of 

 the excellent library connected with the same institution, de- 

 voting his attention more particularly to works on practical 

 mechanics and optics. 



These studies occupied only his evening hours until 1832, 

 when, for a time, he abandoned the spade, and confined his 



