108 A NEW FOEM OF ADJUSTIVE 



the cliair before you, and to wliicli I will now very 

 briefly direct your attention, this condition is at- 

 tained. There is, as you perceive, a total absence 

 of machinery, and I might say of legs also, below 

 the seat. The seat and arms are connected, and 

 move together in a direction not purely vertical, 

 but in that corresponding with the inclination of the 

 hach of the chair. An advantage is thus gained 

 which is not unimportant; viz., that while the 

 vertical range of motion in the seat is itself but 

 thirteen inches, the true and available space 

 between the highest and lowest positions of the 

 seat, measured in the line of motion, is not less 

 than sixteen inches, a range seven inches greater 

 than has hitherto been realized. The great 

 advantages of a practical nature arising out of this 

 form of operating chair are, — First, that it admits 

 of the headpiece being fixed as to height, the level 

 of it being the extreme height of the chair, which 

 is determined in the ordering or selection of it. 

 Secondly, that hy one movement alone, viz., the 

 elevation or depression of the seat, the patient, 

 how^ever tall or otherwise he may be, can with 

 facility be placed in the position required. The 

 mechanism by which the seat is raised and 

 lowered is very simple, and the seat may be ad- 

 justed to the three- sixteenths of an inch, provided 

 such nicety should be considered desirable. There 

 is no noise whatever connected necessarily with 

 the working, and the patient can be raised or 



