PROCEEDINGS OF SOCIETIES. 61 
club a small pair of forceps, manufactured for him by Messrs. 
Yeates and Son, 2, Grafton Street, Dublin, to be used in connec- 
tion with Messrs. Smith and Beck’s “ opaque-disc-revolver.”’ 
He had found, when using the dises as supplied with the re- 
volver, that great inconvenience resulted from having either to 
fasten the object on to the dise with some sort of cement, or else 
to place it in a drop of water to prevent its slipping off when the 
disc was inclined at an angle with the horizon. For practical 
working purposes both of these processes are very objectionable ; 
the first on account of the time it takes and the trouble in 
changing the object, the second on account of many parts of the 
object being covered by a film of water with rounded surfaces, 
which completely alters its appearance, and also because when 
the object is under examination for some little time the water 
dries up and the object suddenly slips out of view, perhaps, in the 
middle of an observation. 
To remedy this he asked Mr. Yeates last autumn to make a 
small pair of forceps to fit into the hole in the “ revolver” like 
an ordinary disc, which he succeeded in doing, and which Captain 
Hutton had found to answer his purpose perfectly. 
In construction it is very simple, and will be readily understood 
from the accompanying figure, which represents a section of the 
forceps drawn about four times the natural size, in order to make 
it clearer; the shaded portion representing that part of the “ disc- 
revolver”’ into which the forceps fit, the unshaded part the 
forceps themselves. 
ED 
ty 
a b Isa disc of brass of the same size and shape of the discs 
upplied by Messrs. Smith and Beck, a round hole of the same 
size as the hole in the “revolver” being drilled through the 
centre. cd Is an arm of the forceps fixed firmly into a 6, and 
has a longitudinal groove cut in the inside, into which the movable 
