BULLETIN 
OF THE 
GENERAL MEETING. 
227TH MEETING. JANUARY 13, 18838. 
The President in the Chair. 
Twenty-six members present. 
Mr. H. FarquHar completed a communication begun at the 
224th meeting on 
EXPERIMENTS IN BINARY ARITHMETIC, 
in which he showed that simple addition involved carrying on sev- 
eral distinct mental operations almost simultaneously and a capital 
of more than fifty propositions committed to memory. Believing 
that the difficulty in mastering, and the mental strain and liability 
to error in conducting, this most important of mathematical pro- 
cesses could be proved to be unnecessarily great, he had compared 
the time occupied in adding a few dozen numbers of six or eight 
figures each with that required when these numbers were expressed in 
powers of 2, the mental work being, in the latter case, reduced to 
counting similar marks and halving their sums. He had found it 
best to give different forms to the marks denoting neighboring powers, 
so as to avoid confusion of columns, and had combined two or more 
of them into one written figure for brevity of expression. About 
seventy combinations of various shapes had been tried, but very few 
of them found economical. In the best notation, however, the addi- 
tion required only three-fourths the time taken with the ordinary 
figures. Had the computer practised as many weeks with the new 
notation as years with the old, the difference would have been much 
more marked; as it was in fact when one unskilled in arithmetic, 
to whom the binary notation had just been taught, tried the two 
additions. The gain in accuracy, with this observer, was even 
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