244 HENRY F. HAILES ON A NEW FORM 



so as to make it more suitable to my purposes. I should not have 

 referred to the circular knife at all, but that I thought my experience 

 might be of some use to any one who might be disposed to try what 

 can be done in that direction. 



In all machines made upon the " Topping " model, it is usual to 

 drive the material intended to be cut into a tube, from the top, or 

 otherwise to wedge it firmly into the tube ; then, by means of a 

 screw or wedge, to drive it out again from the bottom. The result 

 of this arrangement is, that the material at first undergoes some 

 amount of compression, and then when this compression overcomes 

 the resistance offered at the top of the tube, the material comes up 

 with a jump, and you are thus unable to cut sections with any 

 degree of precision ; and after cutting some twenty or thirty slices, 

 you may, perhaps, with good luck succeed in finding half-a-dozen 

 thin enough to mount. 



The machine which I have the honour to bring before you to- 

 night, obviates this defect entirely, and at the same time secures 

 some other minor advantages. 



I will proceed to describe it with reference to Plate xxiii. in which 

 Fig. 1 is a plan view, and Fig. 2 a side view of my machine, as 

 arranged for sawing bone and other hard sections. Fig. 3 is a plan 

 view, and Fig. 4 a longitudinal vertical section of the machine, as 

 arranged for cutting wood or softer sections. Figs. 5 and 6 are plan 

 and side views of the moveable block and pins, used in cutting hard 

 sections, shown detached. A is a short tube, of about an inch and a 

 quarter in diameter, furnished with flanges, B and B 1 , one at each 

 end. The upper one of these flanges serves as a cutting-bed or table. 

 Inside the tube A, slides freely a second tube C, in which is placed 

 the material intended to be cut. This tube C is furnished with two 

 clamping screws, c c, which pass through a slot formed in the outer 

 tube A, and are tapped into a block screwed on the side of the inner 

 tube, C. Inside the inner tube C, and at its lower end, is screwed a 

 nut or boss, D, and through this nut is passed the micrometer screw, 

 E, provided with a milled head, e, and a divided collar, f. This 

 screw is carefully shouldered into a cock or bracket, F, firmly screwed 

 to the lower flange, B 1 . In order to hold the machine securely to the 

 table, it is screwed by its upper flange to a transverse bar of wood, 

 G, which is clamped to the table by the fixed clamp, H. 



The material to be cut may be packed in any convenient manner 

 into the inner tube C, and is secured by the clamping screws, c c. 



