22 THE AMERICAN MONTHLY [Jan 
field of view takes the place of the disc of cover-glass. 
The body-tube has the usual coarse and fine adjustments; 
but as it is inconvenient to move it when once the adjust- 
ments have been made, the stage is provided with an in- 
dependent rack-and-pinion focussing adjustment, as well 
as with mechanical stage and levelling screws for the ob- 
ject under examination. The eyepieces are of the R.M.S. 
No. 3 gauge. The workmanship and finish of this micro- 
scope are of the highest class. The foot is of the solid 
tripod form, the back leg of which might, however, with 
advantage be extended a little more, with a view to gain 
increased steadiness in the horizontal position. The 
price of the stand alone is $80. 
New “D1aGnostic” MicRoscoPEe IN “MAGNALIUM.”— 
In addition to the foregoing microscope, Mr. Charles 
Baker has also submitted for our inspection a ‘“Diagnos- 
tic” microscope (SCIENCE-GossIP, vol. vi., p. 182) con- 
structed almost entirely of “magnalium,”’ an alloy of 
manganese and aluminium, and resembling the latter 
metal in appearance. The total weight is only fourteen 
ounces. The price of the microscope when in this alloy 
is $27. 
BECK’s PoRTABLE “LONDON” MtIcRoscoPpE.—Messrs. 
Beck have recently added a portable model to their list 
of London microscopes (see S.-G., vol. vii., p. 184), in 
which the back leg of the base slides in, whilst the side 
legs fold together, the stage itself being removable. In 
other respects the instrument is the same as the ordinary 
model, fitted with draw-tube, coarse and fine adjust- 
ments, also rack-and-pinion sub-stage, but with the ad- 
ditional advantage of packing into a leather case 94x44x 
24 inches in size. The price of the stand, without ob- 
jectives, eye-pieces, or condenser, is $30. The “London” 
microscope is now made in a cheap vertical form, with- 
out joint for inclination or sub-stage, and with plain 
