CURIOUS COMPETITION

Lake Wakatip Mail, Issue 3614, 18 November 1924, Page 7

CURIOUS COMPETITION

“LIGHTNING” CALCULATOR v. MACHINE. An unusual match between calculatin'!: machines and » “ lightning calculator ” is reported by Jean Cabrerets, writing in ‘ Le Quotidien ’ (Paris). The calculator was the celebrated Frenchman Jacques Inaudi. lie performed prodigies, but nevertheless we are told, the machines won on points. The trial took place in the presence of Professor Maurice D’Ocagne, of the Polytechnic. On one side was a little stumpy man, with, a square' forehead, on the other a battalion of typists, each with a, different kind of machine. Professor D’Ocagne considers Inaudi the most original ol all the lightning calculators. He uses no secret process. Inaudi has stored up in his memory none of the tables in whose construction Professor D’Ocagne himself is an expert, and which simplify calculation to such an extent that a machine is superfluous. He knows only the multiplication table—but be lias his own way of using it. We read : “ Inaudi, at the request of the spectators, gives the squares of numbers containing two or three figures. He multiplies together numbers of four digits. He extracts the cube root of 35,698,267, and while he does it he keeps on talking! But I suspect that this artificial conversation is just ‘patter’ behind which bis brain does the work. “‘How' many minutes in thirty-seven years?’ ‘ 19,447,200 ’ replies Inaudi after a little. It amounts also to 1,166,832,000 seconds, he adds. “He informs another querist that a certain day of a certain month in 1876 was a Sunday. And this is done instantaneously ; question is followed hy answer with stupefying rapidity. “Then my neighbor asks: ‘And June 15, 1924?’ This bothers Inaudi. He lias to work it out as anyone w’ould do with a date in the) current week. “And now' for the famous test. “The machines are made ready. Numbers are dictated. Inaudi repeats them slowly in a loud voice, while the fingers hang above the keys. “ When Inaudi has finished bis statement the judge calls out ‘Go!’ The elicit ing of gears begins. But Inaudi raises l.is finger. ‘1 have finished.’ And the result falls from his mouth before any of 'he machines has obtained it. “Nevertheless it was not always thus. “When the multiplication exceeds four digits in each number Inaudi is sensibly slower, but lie catches up if the two numbers are the same; that is, if he is merely getting a square. “Again, in a very long subtraction Inaudi is visibly slower than the machine. And how could it be otherwise when, after the two numbers have once been registered, a single turn of the wheel is all that is necessary to produce the result? “In conclusion, shall I toll you what I think? “In comparing the three processes — addition, multiplication, and raising to a power—and their inverses—-.subtraction, division, and the extraction of roots (the only ones used by Inaudi) —the advantage rests with the. machine according to the elementary character of the operation. Thus the machine adds more quickly than Inaudi, but he w'ins in the extraction of a root. “There is always a certain degree of complexity in each kind of operation beyond which the machine is at an advantage. Equality would seem to exist at the level of the multiplication of four figures. This is the frontier separating the mechanics of the nerve from that of metal. “From which it appears that the ability of tlie greatest calculators is not unlimited. After an hour of exercise Inaudi is at tke end of his forces. But all the typists are as fresh as daisies ’ “The test is thus decisive. “Resumed methodically, not in an assemblage of a hundred spectators, but before a- small committee and on a very definite experimental plane, it would have psychological significance of great interest in "relation to the mechanism of memory.”