Swift’s Bacteriological Microscope ([Fig. 84]), designed by Professor Wright, of the Army Medical School, Netley, a sufficient warranty of its excellency and perfect adaptation for bacteriological high-class work. One of the advantages connected with this microscope is the facility with which it can be adapted for either high or low power investigation, without the necessity of adding or detaching any part. The objectives, arranged on a triple nose-piece, are approximately in focus when revolved into position for immediate use, thus effecting a saving of time in changing the objective. Moreover, the nose-piece carrying the objectives is of new construction, and fitted in such a way that the entry of dust is rendered impossible.
Fig. 84.—Swift’s Army Bacteriological Microscope.
Fig. 85. Under-Stage of same.
The Abbe condenser, fitted with an iris diaphragm, is mounted on an eccentric arm, so that it can readily be thrown out of the axis of the microscope when not required, without having to re-arrange the focus when again brought into position. The condenser must be turned aside when plate cultivations and preparations of unstained bacteria are being looked over for selection of colonies for mounting, in which case an arm carrying a quadrant with three apertures is brought into position in place of the condenser, the apertures being severally centred by a spring catch and used with oblique light. This arrangement, shown in [Fig. 85], is seen from the under surface of the stage. The stage is sufficiently large, so that when Petrie plates are being examined at the extreme edges there is little fear of their overbalancing.
Fig. 86.—Swift’s Histological Students’ Microscope.
The fine adjustment is the Swift’s Patent Campbell Differential Screw, which offers great facilities for delicate focussing with the highest power objectives. The stand is of the most substantial and rigid form, and thus ensures the microscope from vibration.
The under-stage of microscope ([Fig. 85]) is seen to be of the most approved form.