352 MINT 



certainty of the smallest amount of friction. In ordinary balances the substance to 

 be weighed is placed in a pan, which is on the same level as the pan which contains 

 the counterpoise ; but in Mr. Cotton's balance this condition is of no consequence, so 

 that the counterpoise rests ultimately upon a point which is at (he same distance from 

 the centre of action as the point upon which the matter to bo weighed rests. The 

 counterpoise, o, is placed in a kind of cage, and any variation from this standard 

 is at once indicated, even if it reach only to the thousandth part of a grain. By law, 

 the weight of a coin may vary to a certain extent from a standard weight ; the 

 variation or latitude allowed is called retiwdy, from the Latin ad remediam ; and in 

 weighing, this remedy is taken advantage of by a contrivance much simplified by 

 Mr. Pilcher. The weight of a sovereign is 123-27-1 grains, but it may by law be 

 either 123-474 grains, or it may fall to 123'074 grains. Mr. Pilcher therefore re- 

 duced the counterpoise to the minimum allowed, thus avoiding the placing of a 

 remedy-wire for the light side ; and he then made the remedy-wire q (shown in the 

 first enlarged portion on the left-hand side of the illustration), which is placed on 

 the stand i, upon a peculiarly-formed point indicated in fig. 1542, so heavy that 

 auy blank which would not raise it and the counterpoise, must be within the remedy 

 on the heavy side. In accordance with this arrangement, the continuation of the rod 

 K is terminated by a cage, so that if a coin be so light as to be unable to raise the 

 counterpoise until the stirrup comes in contact with the remedy, it is too light to make 

 a legal coin. This fact being determined, the motion of the machine causes the cam 

 K to bring back the rod L, that it may.be ready when required to push forward 

 another coin, and the forceps Q to grasp the rod" D, while the cam K permits the 

 falling of the rod s, which is nearly counterpoised by the ball in (the precise length 

 of the rod being regulated by the screwy'), until its finger rests upon the indicator. 

 The depth to which s shall fall is fixed by the step (shown in the enlarged portion of 

 fiff. 1541). This is. of course, determined by the forceps, securing D at the position 

 indicated by the weight of the blank. The indicating-finger having come to rest, the 

 continued motion of the machine causes the cam, w, to permit the shoot, u, to fall until 

 one of its steps, v, comes into contact with the indicating-finger, when the lower part 

 of the shoot must be exactly over, and form part of. one of the tubes which terminate 

 in boxes labelled respectively ' heavy," ' light,' ' medium.' The shoot having taken its 

 position, the continued motion of the machine causes the cam K to induce the placing 

 of another coin on the scale-pan F, and this coin, by advancing, pushes off the oue 

 just weighed, which, falling into and through the shoot, passes to the compartment 

 reserved for it. Suppose the newly-placed coin to be too heavy for forming a 

 legal coin, the same operation goes on, but it now lifts not only the counterpoise, 

 but also causes the stirrup at H to lift the remedy-weight. This is a most deli- 

 cate operation, for if a blow, however slight, be given, it would cause unsteadiness 

 in the beam. Mr. Pilcher therefore determined to make the carriage, w, fig. 1542, 

 which supports the remedy-wire, stand upon micrometer screws, by which the 

 remedy-wire is made just to touch the stirrup, without pressure, while it also rests 

 upon the most minute points, formed by cutting away every part of i which is not 

 actually required in fact, shelving it out. The scale-pan F is protected from draught 

 by a lantern, while the coins ara directed into the collar by a guard, as they slide 

 down the hopper. 



Some new machines have recently been supplied to the Mint by Mr. James Napier, 

 but it is not certain that these are cheaper than the old ones. That they are lower in 

 price may be admitted, and they are certainly more convenient in use, from the fact 

 that the wheels shown at F are placed at the back. It is, however, to be regretted 

 that Mr. Napier did not introduce into these new machines the recent inventions 

 of Mr. William Bradshaw, which are supremely simple ; and, now that they are 

 effected, one cannot but wonder that so many minds having been engaged on these 

 machines, improvements such as these have not earlier seen the light. To Mr. 

 Bradshaw, particular!}', great credit is due, for ho was obliged to overcome, not 

 only innate difficulties, but difficulties of position, and these latter were of no 

 mean kind. It is to the credit of the Mint authorities that they finally adopted 

 these improvements, and ordered the necessary alterations to be made in all the 

 machines, 



31 r. Bradshaw' s improvements enable the automaton balances to weigh 30 per cent, 

 more coins in the same time ; yet they permit each coin to occupy a longer space 

 of time in being weighed. This would appear to bo a mechanical contradiction ; 

 but if reference be made to fig. 1540, it will be seen that the cam K pushes forward 

 the lever L, "which ultimately, by the slide, pushes the blanks on to the scale-pan r. 

 By altering the shape of the cam K, Mr. Bradshaw causes it to do its work moro 

 rapidly, and thus leaves the piece on F longer than buforo ; but that this time may 

 not bo lost, ho alters also the chapes of the cam p, and of the cam o, so that the 



