Proceedings of the Polytechnic Association. 737 



for it ;" and it is certainly exact to remark that the weighing balance 

 which is allowed due time for acting will yield far more truthful 

 results than that which is not. One of the great principles necessary 

 to be observed in correct automatic weighing is regularity of motion, 

 and another deliberateness. It has been stated that the law of gravi- 

 tation is infallible, and it is so ; but it must be allowed fair play 

 and freedom in tim3 to insure that infallibility. As the mind of a 

 judge in a court of justice must, if his decisions are to be just, be 

 alike unswayed by passion and by prejudice, so must the mute 

 arbiters of mint coins be free from disturbing causes of any kind, 

 if their conclusions are to be truthful. Having thus, as fully as 

 circumstances will permit, explained the various appliances for 

 giving motion to the automatic Aveighiug machines, let us return 

 to the batches of coins wliich liave been transferred to the judicial 

 department in which they are placed. We will suppose that fifty or 

 sixt J J ournees of sovereigns, stamped, milled, and apparently fitted 

 for the business of active life, are about to undergo the final test of 

 their fitness for duty, namely, that of individual weight. They are 

 first weighed in the 'quantities named, by means of a large hand- 

 balance, of wliich it is only necessary to say tliat it is extremely 

 sensitive. The use of this primary weighing in bulk is that it may 

 furnish a check upon the work people who are to feed the automators, 

 and otherwise wait upon them when in action. Having noted 

 minutely the actual weight of the whole importation of coins, they 

 are forthwith distributed among the self-acting machines. Each of the 

 latter is surmounted by a spout, placed at an angle, and supported 

 by a strut. This spout or slide is the receptacle for coins, and in it 

 they are placed in rouleaux, where they rest until the machine is 

 started. Then a small plate of steel, below the base of the spout, 

 advances and recedes at a speed of twenty times either way per 

 minute. In its advancing movement it presses forward a single coin 

 until the latter rests upon a tiny scale-pan, forming part of a fine 

 steel rod, which is delicately poised and so adjusted as to move the 

 beam, or to be moved by it, as it may be too heavy or too light. 

 Above the opposite end of the beam depends another rod, M^hich, 

 terminating in a loop or cage at the base of the machine, sustains a 

 glass counterpoise weight of the legal minimum weight of a sover- 

 eign. Below the cage, but not attached to it, is a miniature "stirrup," 

 in which rests a piece of platinum wire (platinum is preferred because 

 it is less liable to oxydation) of the precise weight of the legal 

 [Inst.] 47 



