522 
8UMHARY OF CURRENT RESEARCHES RELATING TO 
more constant than the ordinary apparatus. The general arrangement of 
the whole may be gathered from figs. 60 and 61. The water receiver 
is a rectangular box about 110 mm. long, 70 mm. broad, and 35 mm. 
high, and covered over with a glass plate g, perforated with three aper- 
tures for the Microscope, thermometer, and regulator. In this is placed 
Fig. 60. 
General arrangement of the apparatus when in working order. 
the slide o, raised above the bottom from 4 te 8 mm. by strips of glass. 
The water is warmed by means of a copper plate Jc, heated by gas-jets /, 
the flame of which is regulated by a Strieker’s regulator r. The pieces 
of vulcanite c, fig. 61, upon which the copper plate rests, are 3-4 
mm. high, and are fixed on to the stage by the screw-clamps e. The 
thermometer t and the regulator r are kept in position by means of 
a stand (not shown in the illustration) to which they are clamped. 
The light from the mirror is made to pass through a circular aper- 
ture in the copper plate, and then through the bottom of the glass trough 
on to the object. The bottom of the trough at this part is polished 
on both sides. For observing the object a -water-immersion lens is he 
