200 
avoid rational criticism, but they heartily 
desire it, believing that the more widely it 
is known and discussed, the more its ad- 
vantages are understood, the more enthu- 
siastic supportors it will have. 
One of the commonest arguments against 
it, one well known to all of you, I am sure, 
is that it is decimal and not duo-decimal or 
binary, or based upon some devisor other 
than ten. One may admit, for the sake of 
argument, that there would be advantage 
in subdividing a unit by continual bisec- 
tions, but the extremely limited area to 
which this advantage would be restricted is 
almost universally overlooked. It is for- 
gotten that it is only when measurements 
are the result of estimation or judgment 
that this superiority would be felt. This 
being admitted, it further follows that the 
exercise of judgment, wherein bisection may 
possess an advantage, occurs only when a 
single undivided unit is under considera- 
tion, and who will claim fora single instant 
that the difficulty of estimating a fraction of 
a unit is in the least dependent on whether 
that unit isitself the tenth or the eighth or 
the twelfth of another. The plain fact is 
that if one is contemplating the metre as a 
unit it is just as easy to think of or 
set off a half, quarter or eighth or six- 
teenth part as if it were a yard, and 
the same is true of the decimetre or cen- 
timetre when compared with the foot or 
inch. Indeed, one who is accustomed to 
use the metric system speaks and thinks of 
a half or quarter centimetre or a half or 
quarter millimetre without the slightest 
embarrassment, never imagining that he is 
in the least inconsistent or ‘disloyal’ to the 
decimal system. It is curious that this ob- 
jection should be urged by people who have 
long ago become accustomed to a like con- 
dition of things in their currency and who 
would be extremely unwilling to go back to 
a system non-decimal in character. Noone 
will pretend that the sub-division of a dol- 
SCIENCE, 
[N.S. Von. X. No. 242. 
lar offers any inconvenience and every one 
knows that the superiority of the decimal 
system in currency is so manifest that nearly 
all nations have adopted it in one form or 
another. Whatever disadvantages might 
be anticipated in the use of the dollar or 
the metre with decimal sub-divisions are 
involuntarily destroyed by the natural ten- 
dency to refer to smaller units rather than 
to continuous bisections. Thus we may 
talk of a half metre, or a quarter metre, 
but for smaller quantities the decimetre or 
the centimetre are at once chosen, and when 
we wish to go below a half of a cetimetre 
the millimetre offers itself as a convenient 
unit. In the same way we find no em- 
barrassment in taking up the cent asa unit 
when it is desired to go below a quarter of 
a dollar. That the several units thus used 
are decimally related to each other is the 
one fact that makes all of this beautiful sim- 
plicity possible. I have ventured to elab- 
orate somewhat on this point because many 
people are of the opinion that the fact that 
the radix is ten and not two is a really seri- 
ous objection to the metric system. It is 
believed, however, that careful study of the 
principles involved, following the lines in- 
dicated above, will show that this fact is of 
no importance. And it must not be for- 
gotten that our present system is anything 
but binary and that the adoption of almost 
any radix would be an enormous improve- 
ment. But, above all of this, it must be 
remembered that nobody claims any special 
virtue or unique qualities for the number 
ten. It is not because it is decimal that the 
metric system is so far superior to all others. 
The superiority rests upon two great facts, 
the first of which is that the radix of the 
system is identical with that of the system 
of notation and numeration now and for 
many years in use by all civilized people. 
It may well be that a binary or duodecimal 
or some other system of notation would 
offer advantages over that which has prob- 
