pillischee's small student's microscope. 61 



handle, which ordinarily hangs quite freely from the axis of the 

 milled-head, so as not to turn with it, but which can be made to 'grip' 

 it by a slight lateral pressure. A ' slow-motion ' is therefore dis- 

 pensed with. The Stage is furnished with a pair of springs for 

 holding down the object ; a simple method which is very suitable 

 for ordinary purposes, but which requires special care in its use 

 when a slide carrying a drop of fluid beneath a covering-glass is 

 being moved about under the objective, since, if the slide be carried 

 too far towards either side, the covering-glass is displaced by im- 

 pinging against the spring. This instrument is provided with two 

 Objectives, each consisting of a good triplet combination, of hco 

 inches and one inch focus respectively ; and when to these is added 

 a l-4th Objective of moderate angular aperture, it is rendered a 

 very serviceable Student's Microscope. The aperture of the Stage 

 being carefully centered to the axis of the Body, a tube can be 

 screwed into it which will cany a Diaphragm-plate, a Polariscope, 

 or a Paraboloid ; and thus by additions which may be made at any 

 time, either simultaneously or successively, this instrument, of 

 which the first cost is no greater than that of the preceding, may 

 be rendered quite complete enough for the ordinary wants of the 

 Scientific investigator. * 



43. Pillischer's Small Student's Microscope. — The instrument re- 

 presented in Fig. 33 deserves special mention, as having been the first 

 really good Microscope brought out in this country at the price of 

 £5 ; and as having gained for its constructor the award of a Medal 

 at the International Exhibition of 1862 'for cheapness combined 

 with excellence. ' This Microscope is framed upon the Ross model, 

 and is provided with a fine adjustment as well as with the rack-and- 

 pinion movement. The Body is furnished with a sliding tube, by 

 pushing-in which it may be shortened for packing ; thus enabling 

 the instrument to be put away in a very small compass. The Stage 

 carries a simple but very convenient Object-holder, consisting of a 

 back -and -front piece pivoted to the upper left-hand corner of the 

 stage, and of a transverse bar, of which the left-hand extremity is 

 pivoted to the lower end of the preceding, whilst its right-hand 

 extremity, which projects beyond the stage, is kept down upon it 

 by a spring applied to its under surface. From this transverse bar 

 there project forward two tongues, on which the slide bearing the 

 object is laid ; and these tongues are furnished with springs for 

 keeping the slide in place. By applying the right hand to a pin 

 which projects upwards from the free end of the transverse bar, 

 motion may be readily given to the object in any direction ; whilst 



* This Microscope being fitted with the ' universal screw,' now generally 

 adopted by English Opticians, may be employed by any Microscopist 

 with the Objectives and Accessories he may already possess, and will be 

 found very convenient for Sea-side use. On the other hand, those who 

 commence with the Objectives specially provided for this instrument, 

 may at any time substitute for them Objectives of a higher class. 



