From Carpenter, Wm. B., “The Microscope and its Revelations”, 5th ed., 1875, pp. 83-84. :

“A more substantial and elaborate form of dissecting microscope, devised by the late Mr. R. Beck, is represented in Fig. 34. From the angles of a square mahogany base, there rise four strong brass pillars, which support, at a height of 4 inches, a brass plate of 6 1/2 inches square, having a central aperture of 1 inch across; upon this rests a circular brass plate, of which the diameter is equal to the side of the preceding, and which is attached to it by a revolving fitting that surrounds the central aperture, and can be tightened by a large milled-head beneath; whilst above this is a third plate, which slides easily over the second, being held down upon it by springs which allow a movement of 1 1/2 inches” in any direction.

The top plate has an aperture of 1 1/2 inches for the reception of various glasses and troughs suitable for containing objects for dissection; and into it can also be fitted a spring holder, suitable to receive and secure a glass slide of the ordinary size. By turning the large circular plate, the object under observation may be easily made to rotate, without disturbing its relation to the optical portions of the instrument; whilst a traversing movement may be given to it in any direction, by acting upon the smaller plate. The left-hand back pillar contains a triangular bar with rack-and-pinion movement for focal adjustment, which carries the horizontal arm for the support of the magnifiers; this arm can be turned away towards the left side but it is provided with a stop which checks it in the opposite direction, when the magnifier is exactly over the centre of the stage-aperture. A concave mirror, when not in use, lies in a recess in the mahogany base.“ The wood carrying case has 3 more lenses .

The microscope is signed “R & J Beck, 31 Cornhill, London”