58 NEW YORK STATE MUSEUM 



semicircular grizzly set close beneath. Through the one-sixteenth- 

 inch spaces of this grating, the peat drops as a mixture of fine 

 particles and dust, damp to the touch." The pulverized peat is 

 then passed through the drier, after which it is briquetted in what 

 is known as the D'obson press. This press employs a resistance 

 block instead of the open tube, and it is claimed that friction is 

 almost entire Ij' eliminated. A large number of dies are used with 

 each punch, so that the temperature is kept low. " The briquet 

 is allowed to remain in the die for one cycle of the system and is 

 then subjected to an'other compression by a second briquet being 

 formed on top of it. Immediately after this, it is expelled and 

 the second block takes its place. It is found after the first com- 

 pression, a certain amount of expansion, about one-eighth of an 

 inch in the length of the briquet, takes place, due to the escaping 

 of the imprisoned air forced into the briquet by the descending 

 punch, and this expansion the second compression counteracts, 

 leaving the briquet more solid and compact. There are two 

 punches in each machine, and for each punch a die block contain- 

 ing eight snugly fitting dies. The dies are heavier in the lower 

 end where the compression takes place. The base block against 

 which the briquets are formed, remains rigid unless for any 

 reason the strain exceeds the working pressure, when a set of 

 spiral steel springs on which the block rests take up excess 

 pressure and prevent any breakage. The down-thrust of the 

 punches is imparted by two heavy eccentrics faced with roller 

 bearings, and Avith each stroke of the punch the die block 

 is turned through one eighth of a revolution. Working in the 

 next die to the compressing punch is the releasing punch, 

 which expels the finished briquet, while the third receives an 

 oil swab, which coats the inside of the die with a film of crude 

 petroleum to lessen the friction and facilitate the expulsi'on of the 

 briquet. The two punch system of the press acts reciprocally, a 

 stroke being delivered at every half revolution of the eccentric 

 shaft. With each down stroke, the. compressing punch forms a 

 briquet on top of the 'one previously made in the same die, the 

 discharging punch expels from the next die the bottom or com- 



