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SUMMARY OF CURRENT RESEARCHES RELATING TO 



greatly facilitates mounting. The ribbon is unwound from the drum on 

 to the plane, where it is cut to the desired lengths. The continuous 

 ribbon does away with the bother of piecing bits together, as is frequently 

 necessary when mounting from short strips laid on paper. 



Directions for making. Material : — All the materials necessary for 

 making the machine are easily obtained, and at slight expense. The 

 wood used was poplar and yellow pine, taken from an old packing- 

 box. A 14b. coffee-tin was made to serve as the cylinder or drum. 

 Dimensions : — 1. The base, 9 x 6 x \ in. (fig. 46, A). A slot, 2 \ x \ in. 

 (fig. 47, 10), is cut in the centre to accommodate the winged nut (9), 

 which fastens the uprights (3) to the base. 2. The base to which the 

 uprights are fastened, 7 x 3 x \ in. A 4^-in. hole is bored in the centre 

 of this base to pass the screw of the winged nut through. 3. The 

 uprights, 2 x 3 x \ in. The width narrows 4 in. from the bottom to 



Fig. 47. 



l\ in. Slots, 1 x I in. are cut in the tops of the uprights (fig. 46, D) 

 to" accommodate the axles of the drum. The uprights were made for the 

 Leitz Base Sledge Microtome, and though the height to which they raise 

 the drum works very well with the rotaries, 2 in. might be cut from their 

 length with advantage. 4- These are pegs that are inserted 4f in. from 

 the base to carry the inclined plane, shown in fig. 47, 11. 5. The 

 axle support. This is a disk of wood 2 x \ in., through the centre 

 of which a \-m. walnut axle is thrust. The end of a maple-spool is glued 

 to the top of the disk to serve as a bearing (fig. 46, B 3). 6. The drum. 

 The lid is soldered on to a 1-lb. coffee-tin, the measurements of which 

 are 6 x 4 in. The can is covered with blotting-paper. This drum will 

 carry about 14 ft. of |-in. ribbon. 7. The drum pulley, 2 x \ in., and 

 grooved as shown in" the diagram. The belt runs from this pulley to 

 one made by fastening the ends of a small spool together, and which is 

 secured to the inner surface of the driving wheel. 8. The driving 



