738 Teaxsacttons of the American Institute. 



difference or " remedy " allowed as a compensation for imperfection 

 of workmanship. During the three seconds which each piece of coin is 

 permitted to rest upon the scale, its fate or fortune is decided. If its 

 weight exceeds the legal point one iota, it naturally depresses the other 

 end of the beam upon which it has been placed, and as a consequence, the 

 other end is raised, and with it the stirrup and remedy wire. This is 

 fatal. The shde presses forward another candidate,and this latter pushes 

 the condemned coin off its seat, and takes its place. The culprit t^dls 

 through a flat, brass tube, and is conducted into the " too heavy " 

 recess below the machine, there to await its punishment, a return to 

 the crucible. The lowest office of the conducting tube is made to 

 vibrate over three spaces of slats below, and these lead to the " light," 

 "medimii," and "heavy" compartments. At the instant the two 

 heavy coin were dismissed into the tube, the lower mouth of the lat- 

 ter was held by a mechanical finger, itself governed by the movement 

 of the beam, over the innermost or " too heavy " slot. The succeed- 

 ing coin may, for illustration, be supposed to err on the other side of 

 the standard. In this case the glass counterpoise descends, the 

 defaulter is detected, and summarily ejected iiTto the condemned cell 

 for "light weights." When an intermediate or medium coin is placed 

 on the pan, the beam maintains its equilibrium during the whole of 

 the three momentous seconds, and the coin descends into the 

 " accepted" chamber. In this way these automaton judges try, and 

 acquit or condemn all coins submitted to their judgment. They pur- 

 sue the "even tenor of their way" from morn till night, and collect- 

 ively are capable of deciding upon the characters, and awarding the 

 destinies of 200,000 sovereigns per day. This system of automatic 

 weighing is economical in the highest degree ; for, although each 

 machine has cost more than $1,000, they have, to use a common 

 expression well understood, paid for themselves over and over again. 

 From the careful manner in which aU the antecedent operations are 

 performed at the mint, not more than five per cent of the coins weighed 

 in the mint balances are rejected by them. At the close of each day 

 the whole of the coins in the weighing room are again weighed in 

 journees, at Oertling's balance ; those which are " good " being sent 

 forward for circulation, and the rejected going to the melting pot. 



In relation to the item on phosphorescent photographs. Prof. Yan- 

 derweyde remarked that after the diamond has been exposed to the 

 sun for some time and then taken into the dark, it will shine. Some 

 diamonds will exhibit brightness for hours, and others only for a few 



