MINI? 347 



720 ounces, and placed in tags ; each bag, therefore, contains four journeys of about 

 180 ounces each. These bag's are placed on trucks and taken into the marking-room, 

 where they are emptied, and the Blanks submitted to the action of a machine whose 

 operations reduce the diameter of each blank by compressing its edge. It is called 

 Jones's Edge Compressor. Fig. 1537 represents Mr. Jones's machine. The blanks 

 are placed in the Hopper A, and fall by an incline into a tube B until they rest at c, 

 on a notched wheel D. As D revolves each of its notches carries away the bottom 

 blank of the pile from the tube B, and leaves it to slide down the tube E till it reaches 

 the block F. The block F is cut with a narrow groove, which exactly corresponds 

 with the groove G a on the plate or disc G. The disc o revolves, and as the blank slides 

 down and comes with some little impetus against the groove in the block F, the 

 groove o a catches it, and causes it to take two revolutions between the disc G and the 

 block F, finally permitting its escape at H, when it falls into i, being now reduced in 

 diameter and thicker on the edge, but its centre remaining as it was before. The 

 machine is driven by J, the shaft of which carries a reduced rigger for the driving of 

 K. The hopper is supported by the rod L. The distance between F and G represents 

 the diameter of the blank after its edge is compressed, this distance being determined 

 by the screws seen at M. Blanks of all diameters may be compressed at this machine 

 if the block F and the plate or disc G bo removed and replaced by others, neither 

 operation taking many minutes. The edges of the blanks are compressed at the rate 

 of 700 per minute. A boy of fourteen could work this perfectly well, and with more 

 convenience now that the hopper is replaced by such an one as is used to supply Mr. 

 Cotton's weighing machine. The edge of the blank is compressed with a view to 

 prepare it for the crenating to be given by the collar in the after process of conversion 

 into a coin. 



The blanks are conveyed from the edge-compressor to the annealing-room, where 

 they are freed from oil and placed in copper tubes, some charcoal being sprinkled on 

 them to prevent the action of atmospheric oxygen on the alloy so far as possible. 

 The tubes are then placed- on iron carriages, and run into reverberatory furnaces, 

 heated by Juckse's smoke-consuming apparatus, where they remain for an indefinite 

 period. The furnaces are like that represented in the rolling-room for annealing the 

 fillets in copper-tubes. To anneal the blanks, the temperature should be raised 

 rapidly until the tubes attain a full red heat ; and the time allowed for the operation 

 should be from twenty to twenty-five minutes at the utmost. After the heating, the 

 tubes are withdrawn from the furnace and placed on the floor of the room, till the 

 blanks are assumed to have become cool. The charcoal is then sifted away, and the 

 blanks cleaned and taken to the press-room to be coined. There are, nevertheless, 

 some soiled blanks, which are blanched in dilute sulphuric acid. 



The blanks taken from the annealing-room are each by a single blow of the coining 

 press converted into coins possessing the obverse and reverse impressions, as well as 

 the crenated edge, which is one of the means employed to protect the coin from the 

 peculations of the clippers, those enemies to coin of all ages and all countries, but 

 whose business has departed, not so much from the crenated edge as from the better 

 balances placed in the hands of almost every man certainly within reach of every 

 man. The crenated edge is known to be no protection against the plan called 

 ' sweating,' and which is effected by shaking the new coins in bags, when perhaps an 

 ounce of gold may be obtained from 1,000 new sovereigns. The sovereigns thus 

 treated are passed, and the operator makes his profit, but the light gold is detected 

 by the balance, not by the eye. This is not the place to discuss such a question, so 

 that we pass on to a description of the machine which is used to give the image and 

 superscription to coins which will be current in accordance with the law. 



The engraving illustrates Mr. Boulton's screw coining press, which alone we 

 describe, although there are also lever presses in the Mint. The blank is laid by the 

 automaton hand L, on the lower die ; L, retires, and the collar then rises and encloses 

 the blank, while the upper die, fixed to the main screw of the press by the securing 

 apparatus 4, comes down with a blow estimated to be about forty tons, and, striking 

 the blank, causes its particles to re-arrange themselves, and to assume the form given 

 by the engraving on the dies and the crenated collar which surround them ; in other 

 words, the plain blank becomes by one blow a coin in every way complete. The 

 following description will convey to the reader an explanation of the processes as they 

 arise. The press having been set at rest, with the fullest space between the dies, is 

 called up that is to say, the upper die has been raised from the lower die, and in 

 this position the automaton hand L has conveyed a blank from the tube K to, and 

 holds it over, the lower die ; upon the first motion of the press downwards, the 

 eccentric wheel or cam 7 causes the lever H, which works on the pivot 1, to withdraw. 

 The lever H may be lengthened or shortened at pleasure by an arrangement at the 

 lower end. The first motion towards the withdrawal of L causes its finger or hand 



