Let the weight which will produce equilibrium after transposition be found, and with the former weight be reduced to the same denomination of weight: and let the two weights thus expressed be multiplied together, and the square root of the product will be the true weight.

Example. - If one weight be 7 lbs., and the other 9 1.7, 7 + 9 1.7 = 64 and the square root of 64 is 8; hence 8 lbs. is the true weight.