1180

PRANCE.

Deleuil’s Delicate Balance.

The chemical balances oi the exhibitor are also verysimple, and turn with the two-thousandth or three-thou-sandth part of the weight which they will carry. Theassay balances are furnished with gilt weights of greataccuracy.

The annexed illustration, fig. 3, represents the electric-light regulating apparatus, invented by the exhibitor. Itis simple in construction, and may be used in all positions;it is furnished with spherical or parabolic reflectors, and

supplied by a modified Bunsen battery of fifty elements,and calculated to produce the most intense light.

In the illustration, fig. 4, the above apparatus is shownin conjunction with the microscope. It acts with the sameelectric battery, gives perfectly luminous discs of II 3 feetin diameter ; and it is arranged so that, notwithstandingthe great focus of heat, bodies can be exposed to itsaction for a long time in any experiment without under-going any change.

Pig. 3.

Pig. 4.

Deleuil’s Electric-light Regulator.

Deleuil’s Microscope and Regulator Combined.