OILS 441 



cylindrical bag, with open ends, formed of fustian, hair-cloth, or similarly pervious 

 material, is made of such a diameter as will tit closely to the inside of tho tube n ; 



and within this bag is placed a cylinder, of wiro gauze or finely-perforated metal. 

 The steel collar t is forced into the end of the wire gauze, by which it becomes driven 

 into the recess formed at ', and is securely held there by the pressure of tho collar t. 

 Tho bag and wire gauze are then tightly stretched over the end, w 2 , of the tube, 

 and the collar u driven tightly on, by which means tho bag and wiro gauzo arc 

 securely hold in their places. Tho lining-tube, n, is then put into tho pressing- 

 cylinder as far as the shoulder, g. A tubular-piece, k, is next put in, and brought 

 into contact with the collar u, and then the gland, i, is screwed home, whereby tho 

 lining n is firmly retained within the pressing-cylinder. The end of the pressing- 

 cylinder is contracted at /', and forms a shoulder for tho abutment of the collar j, 

 the diameter of the aperture in which regulates the pressure to which tho matters 

 \inder operation are subjected. Within the tube n there is fitted a solid plunger, h, 

 which receives motion from the crank d by means of the connecting-rod I, tho pirallel 

 motion .being obtained by the wheels, in, on the cross-head, traversing on tho side 

 of the bed-plate at a*, a? is a hopper bolted to a flange, f 2 , on the pressing-cylinder, 

 and communicating therewith. There is also an opening in the tube n at ', corre- 

 sponding with the opening into the hopper, so that any materials placed in the hopper 

 may fall into the tube n, when the plunger k is withdrawn from beneath tho opening. 

 At that part of the pressing-cylinder which is occupied by the ' lining,' there are 

 drilled numerous small holes, f*, which communicate at various points with the spiral 

 groove in the tube n. On the outside of the pressing-cylinder there are formed two 

 collars, f 4 , f 4 , which abut against the projecting pieces, a 8 , and caps, e, and cause 

 the pressing-cylinder to be retained firmly in its place. When steam-power is to bo 

 employed to give motion to the oil-press, it is preferable to have the crank which is 

 actuated by the steam-piston formed on the end d 1 , on the crank-shaft of the oil-press, 

 and placed at such an angle to the crank d, that when the crank d is pushing the 

 plunger k to tho end of its stroke, the steam-piston will be at the half-stroke, 

 whereby tho motive-power applied will be the greatest at the time that the press 

 offers tho most resistance ; and the steam-piston also, when passing its dead points, 

 will have to overcome the friction of the machinery only, as the plunger, k, will be in 

 the middle of its back-stroke. When any other motive-power is applied to turn tho 

 crank d, it will be necessary to put a fly-wheel on the shaft d 1 , as also such cog-wheels 

 as will be necessary to connect it with the first mover. When this apparatus is to bo 

 employed in expressing linseed-oil, the seed, after having been ground and treated in 

 the way now commonly practised, is put into the hopper, and, motion being trans- 

 mitted to the crank in the manner before described, tho plunger k will commence a 

 reciprocating movement in the tube n of tho pressing-cylinder. Each time that it 

 recedes in the direction of tho crank it will move from under tho opening in tho 

 hopper, and allow a portion of the seed to fall into the tube, while the reverse motion 

 of the plunger will drive it towards the open end of the cylinder, its passage being 

 much retarded by the friction against the sides of tho tube-lining, but chiefly by tho 

 contraction of the escape-aperture through tho collar .;', which will produce a con- 

 siderable amount of resistance, and consequently tho plunger will have to exert an 

 amount of pressure upon the seed in proportion as the escape-aperture is made larger 

 or smaller. The collar, j, is made moveable, and, by withdrawing the plunger entirely 

 from the tube, it can be exchanged at any time for another having a larger or smaller 

 opening. Tho lining may at any time be removed from the cylinder, and tho worn 

 parts removed when found requisite. The action of tho plunger is somewhat like that 

 of the plunger of an hydraulic press-pump, the seeds being pumped in at one end 

 of the pressing-cylinder, and allowed to escape at tho other, while tho whole of tho 

 interior of the pressing-cylinder that contains seed is lined with hair-cloth or other 

 suitable pervious material, and, that it may bo protected from injury, is covered with 

 wire gauze or finely-perforated metal. The bag is thus completely defended from 



