MancJiesier Memoirs, Vol. xlvii. ^1903), No. %. 5 



the " magic " effect did not appear until the strain was 

 reh'eved, when the effect was very marked, as is shown 

 in the accompanying illustrations, Fig. i being the raised 



design at the back of the mirror, and Fig. 2 the " magic 

 effect produced by reflection from the polished surface. 



