;u)7 



II. Te.mpkratuke Box. 



Tliis triii]ici-;itui'c lio.\ is iiiiidc of jiiih'juiizi'd iidii. It is li.'i cm. long, 

 9 cm. -wide ami :! cm. (Icc|). all inside moasuics. It is licld Id tlic stage 

 of tlic inicr()sc(»i)(' ])y means ol' a cnrxcd ii'oii clamp lidolscd ovi'i' llie edge 

 of the l)o.\ at A. Near the lower siiU; Ji is a rectangular slit 4 cm. wide 

 and 4 mm. high, extending entirely across the box for the reception of a 

 slide carrying the object for observation. P>y noticing Fig. 2 it will be 



1 !, 



Kiir. 2. 



seen thai tlie slil. P., is elevated ahont L' mm. alioxc the bottom of tlie l)OX 

 as at C, tints allowing the liol or I'old water used to flow undi-r and all 

 around the space occupied by the slide I'.y this means the temperature 

 may be increased or decreased as desired, in 1'. to the most jterfect state 

 of efficiency possible in sncii a simi»le contrivance. At 1) is a cylindrical 

 tube 3 cm. high and L'..') < ni. in diameter for tlie rece])tion of tlie oli.jeetive. 

 In Fig. 2 both the tube D anil the side of the box toward the oliserver 

 are cut jiartly away to sliow tlie interior. The loj) is jirovided with a 

 lid. By means of a projier mixture of salt and ice it is possible to reduce 

 the temperature In the slit B, as shown by the thermometers kept con- 

 stantly in the si)aces E and E\ to zero centigrade or below. If, iiowever, 

 a high iemperature is desired, this may be a<-coni])lished by jilacing a 

 flame under the end of the bo.x 1" which projeels over the stage of the 

 microscojie. Or one may arrange a vessel, somewhat higher than the 

 box on the stage of the microscope, and by jilacing a lani]) under this 

 vessel, which is nearly tilled with water, easily heat it to any desired 

 temperature as shown by a thermometer. This heated water could then 

 be sii)hone(l into the box A and out again, and in this way the desired 

 temperature In !', obtained. The iiillow and outllow to A can easily be 

 regulated and made uniform by opi'iiing or closing pinch-cocks fastened 

 on the rubb;'!- tube. Injury to the microscoi)e is jirevented by ;i sheet of 

 asbestos placed on the stage. This temi)erature box can be turned either 

 to the right or left or turned and used in any angle of 18()° or less. 



