4-3S SirD. Uvewsier^s Accouni of a Chinese Mirror, "which reflects 



small quantity of thick ink on the point of a pin, and drop- 

 ping it on a clear plate of glass, by which means a sufficiently 

 even circular edge is produced, the disk being about ^'^th 

 inch diameter. 



Oxford, Nov. 4,1832. 



LXXVIII. Account of a curioiis Chinese Mirror ^ -jahich re- 

 jects from its polished Face the Figures embossed upon its 

 Back: By SirD. Brewster, K.H. LL.D. ^c. 



VIT'E have just received, through the kindness of George 

 ^ ^ Swinton, Esq. of Calcutta, whose zeal for the promotion 

 of science is never relaxed, an account of a curious metallic 

 mirror, which had been recently brought from China to Cal- 

 cutta, and which was then amusing the dilettanti and per- 

 plexing the philosophers of our Eastern metropolis. 



This mirror has a circular form, and is about five inches 

 in diameter. It has a knob in the centre of the back, by which 

 it can be held, and on the rest of the back are stamped, in re- 

 lief, certain circles with a kind of Grecian border. Its po- 

 lished face has that degree of convexity which gives an image 

 of the face half its natural size; and its remarkable property 

 is, that when you refect the rays of the sun from the polished 

 surface, the image of the ornamental border, and circles stamp- 

 ed upon the back, is seen (we presume in shadow) distinctly re- 

 flected on the "wall. 



The metal of which the mirror is made, appears to be what 

 is called Chinese silver, a composition of tin and copper, like 

 the metal for the specula of reflecting telescopes. The metal 

 is verv sonorous. The mirror has a rim of about jth or ^th 

 of an inch broad, and the inner part, upf)n which the figures 

 are stamped, is considerably thinner. 



Mr. Swinton states, that no person he has met with has 

 either seen or heard of anything similar to this mirror. The 

 gentleman who brought it from China, says that they are very 

 uncommon in that country; and that this one, with a few 

 others, was brought by a Dutch ship from Japan several 

 years ago. On the back of one of these was a dragon, which 

 was most distinctly reflected from the polished side. Mr. 

 Swinton also mentions that he has seen another Chinese cir- 

 cular mirror, which is curiously embossed on the back. It is 

 eight inches in diameter; but as its polish is rubbed off", he has 

 not yet been able, by replacing it, to ascertain if it reflects a 

 picture similar to the figures stamped upon its back. Mr. 

 Swinton adds, that the original mirror first described, is to be 



