170 



TRANSACTIONS OF THE 



within endless racks, toge- 

 ther with the arrangement 

 of the flying apparatus. To 

 enable you to form an idea 

 of its arrangement and ope- 

 ration, v,'e will give as clear 

 and explicit a description 

 of its various parts, and 

 their movements, as possi- 

 ble. In tlie first place the 

 bed is the foundation of the 

 press, and the body of the 

 framework ; on each corner 

 of the bed are secured with 

 great firmness, four legs, 

 shaped to suit the various 

 purposes of stands, &c., for 

 the driv'g machinery; lugs 

 or ears are cast on the legs 

 near the bed, for the pur- 

 pose of sustaining the end- 

 less racks. The racks are 



Cylinder Printing Press. SO fitted tO the lugS that by 



means of set screws they are raised or lowered to set the impres- 

 sion. The endless racks have their teeth on their inner surface. 

 In form they are straight as far as it is necessary to reciprocate; 

 the ends are exact half circles; the outside form of a condensed 

 letter 0, would give a fair illustration of their shape; in the cen- 

 tre and back of the racks is a slide exactly equi-distant from the 

 internal surftice of the racks. The impression cylinder has on 

 each end of its shaft pinions, whose pitch line are the size of the 

 cylinder. These pinions run in the two endless racks; the shafts of 

 the cylinders extend beyond the pinions far enough to form a jour- 

 nal; these journals revolve in boxes, one side of which acts as a 

 slide, and are adjustable, so as to regulate the mash of cylinder 

 pinions and endless racks; in their operation they reciprocate 

 and revolve around the centre slide of endless racks, thus keep- 

 ing the cylinder pinions always in gear. The cylinder is driven 



