356 A. DAIGGER & COMPANY, CHICAGO, U. S. A. 



6342 



6343 MICROTOME Spencer Lens Co., No. 820. The Spencer Rotary Microtome is 

 an original construction. It is intended for the most accurate and careful 

 work. An inclined plane feed, which is independent of the up-and-do.wn 

 movement on the perpendicular support, overcomes the inaccuracies inher- 

 ent in other rotary microtomes. The most important element in a micro- 

 tome is an accurate and reliable feed mechanism. This, and rigidity, are 

 vital. These points are paramount in this instrument. 



The feed is so arranged that it can be set for sections of any thickness, 

 from 1 micron to 60 microns, by turning the knurled button at the back 

 of the case until the number representing the desired thickness appears 

 opposite the indicator at the small opening in the side of the case near the 

 balance wheel. 



The total excursion of the feed is 37 mm., allowing a sufficient range 

 for cutting a complete series of a very large object without the necessity 

 of a break due to resetting the knife and feed mechanism. 



The object clamp is a part of a ball which fits into its socket so 

 uniquely that it is clamped as solidly as though it and its socket were one 

 piece. The object is easily, accurately and delicately oriented to any de- 

 sired angle. The angle can be changed in any plane without interfering 

 with any angle already attained in another plane. The object may easily 

 be rotated. 



The up-and-down stroke of the object clamp is 50 mm., which permits 

 the cutting of very large sections and gives sufficient stroke for celloidin 

 cutting. 



The knife is fastened by two clamps, each of which clamps the knife 

 at the back and along \Y$ inches of the edge as well. It may be turned to 

 any desired angle, and the clamps may also be moved toward one another 

 to bring them as near to the ribbon as desired to gain additional rigidity. 

 When the clamps are thus drawn together, the knife may be moved so that 

 practically all of the cutting edge can be used before the necessity of 

 resharpening. The adjusting screws provide for knives of different widths. 

 The balance wheel is grooved, so that the instrument may be run by a 

 motor. 



Spencer Rotary Microtome, with one knife, handle and back for 



sharpening, and with three object discs $130.00 



Knife holder for celloidin sections extra, 15.00 



Knife for paraffin sections extra, 7.00 



Knife for celloidin sections extra, 7.00 



Adjustable knife holder, permits entire block carrying knife to be 

 shifted sideways, \y 2 inches (3 inches in all) either way from 

 center extra, 10.00 



Table with motor, and speed regulator enclosed for 110-volt direct 



current extra, 75.00 



Same for 220-volt direct current extra, 90.00 



