118 Mr. W. Keddie on the Early History and Proceedings of the Society. 



proposed — amongst the rest, one by the Messrs. Hart, to have one or 

 more reflectors placed above the dial, so as that the incidental rays, fall- 

 ing therofrom on the gilt letters and hands, might be reflected down to 

 the street, according to the law of optics, that the angle of incidence is 

 always equal to the angle of reflection. Mr. Lumsden rehearsed to the 

 Society a report he intended to submit to the Police Board on small 

 lamps, requesting the Society in the meantime to institute an experi- 

 mental investigation into the most efiicient method of lighting. The 

 name of Dr. Thomson, the Professor of Chemistry, and long afterwards 

 the President of the Society, is for the first time mentioned in the 

 minutes in connection with the lighting of the city. A letter from 

 Dr. Thomson, addressed to the Police Board, was produced in the 

 Society, recommending rather half the number of lamps, and a greater 

 flame in each. Mr. Lumsden's small lamps were intended to evapo- 

 rate the moistui'e formed within the globes ; and when mounted on 

 the lamp-posts they were found to answer the purpose perfectly, so 

 far as the moist atmosphere within Mas concerned ; but the conditions 

 of the cold and humid external air not having been consulted with equal 

 foresight, the effect of the first shower of rain on the hot surface of the 

 glass could scarcely have been exceeded by one of the street riots of 

 those tm'bulent times, and the Pohce Board soon found it necessary to 

 exchange their new lamps for old ones. 



In the course of the year, Mr. Andrew Liddell exhibited to the 

 Society a model of Messrs. Harts' apparatus for illuminating the dial of 

 the Tron steeple, which had been approved of and adopted, the two 

 ingenious brothers receiving a formal vote of thanks for then* contriv- 

 ance from the Police Commissioners. 



Dr. James Watt, who had taken an active interest in the Society for 

 many years, died on the 3d of March, 1821. 



Mr. Eobert Hastie having taken charge of the improvements going 

 on this year in the old bridge at the foot of Stockwell Street, after the 

 death of Mr. Crichton, the civil engineer, described to the Society the 

 plan which was adopted of widening the bridge by projecting the path- 

 way on either side upon iron arches. 



Mr. Ancbew Smith of Mauchline, well known as a maker of snuff- 

 boxes, exhibited an instrument for tracing drawings. The Society com- 

 mended this invention, to which they gave the name of Apograph ; it 

 was employed by Mr. Smith in producing figures in relief upon the lids 

 of his celebrated snufl'-boxes. Repeated discussions subsequently ai'ose 

 on the claims of successive inventors of instruments similar to Mr. 

 Smith's. 



Tlic SoL'ictv consisted at this time of 120 mombcrs, each of whom 



