ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 127 



very convenient arrangement of mounting apparatus, including trays, 

 reagents, and instruments. The knives, scissors, &c., are, as will be 

 seen, arranged on a hinged cover to the inside of the lid, which is of 

 extra depth, 



Klbnne and Muller's Pendulum Object-frame or Bacteria- 

 finder. — Messrs. Klonne and Mliller have devised this apparatus 

 (figs. 10 and 11) for readily finding small objects. It may be fitted 

 to any Microscope, and can be traversed over the whole of an object 



by means of two graduated motions, so that the position of any point 

 may be marked and recovered without difficulty. The frame (fig. 10) 

 which holds the slide, is moved backwards and forwards by a swing- 

 ing motion about the fixed point d, and from side to side by the 

 traversing screw c. These motions are measured by the graduations 

 on the circular slot at b, and by the millimetre scale and vernier at a. 



To fit the frame to the Microscope, the piece a is swung out of 

 the slot b and brought round to the left of d ; the framework hfg is 

 pushed forward over the stage from behind until the rests e e lie upon 

 the stage, and / upon a projection at the back of the pillar. The 

 screw g presses against one side of the stage, and h is screwed up to 

 the other. / and g are adjusted by the makers so that the line d c 

 (c being near the centre of the slot) passes through the centre of the 

 stage. The object is then inserted into the frame a from below • it is 

 held in position by the spring shown at the upper side, and is pressed 

 against the stage by the two springs below when the frame has been 

 swung back into the position shown in the figure. 



The object having been placed by means of c so that its edge is at 

 one side of the field of view, is searched from top to bottom by the 

 motion about d; it is then shifted by means of c through a distance 

 equal to the width of the field and a second vertical strip of this 

 width is traversed by the pendulum motion ; the process is repeated 



