667 



more freely escaping gas to increase the flame. The adjustment 

 of the mercury to the exact height require 1 is accomplished by a 

 screw which works through a steel collar on the side of the glass 

 tube and which by working in or out gives the requisite change of 

 capacity to the reservoir. This adjusting screw is the most diffi- 

 cult part of the apparatus for construction by an amateur, and 

 may be omitted, the adjustment being accomplished by sliding the 

 steel tube up or down until its lower end just touches the mercury 

 after the desired temperature has been reached, in which case it, 

 of course, is not cemented into the glass tube but made to slide 

 into it through an air-tight packing. The proximity of the objec- 

 tive probably reduces somewhat the temperature of the object, 

 and if great exactness is essential,.an additional current of hot 



the objective. The apparatus is described and figured in the 

 "Quarterly Journal of Microscopical Science." 



Cox's Turntable.— Miller Bros, of New York have made an 



ppeared during the past ye 



alter 8 tTr^suethe ^iWisteTbTMessrs. H. O. Hought 

 of Boston, Mass., the former proprietors having v 



edited by A. S. Packarc 



It is hoped that, from the sub, 

 duct of the magazine by kind frier 



Much more matter, equivalent to over fifty pa, 



ease of 1 



, due to the 



