[78-L] Edison Trademark

[marimbamoods at comcast.net]

diamond discs, both etched and labeled, show edison's signature superimposed over a trademark with the statement "a product of the edison laboratories." 


depicted in that trademark logo are two objects that are probably intended to be representative of a laboratory. on the right i am guessing is a mortar & pestle, and on the left is an object i can not identify. it seems to have three legs and a tapered tube of some sort. 


can anyone explain this image? 


best, david harvey