62 



SCIENCE. 



[N. S. Vol. IV. No. 81. 



might be devised, based on absolute zero, 

 which would be really decimal, have no 

 minus readings and be in accordance with 

 the metric system. 



It is unfortunate, theoretically,. at least, 

 that the meter is not exactly a ten-mil- 

 lionth of the earth's quadrant. But the 

 question with us in America is, shall we 

 adopt as a unit the platinum-iridium bar 

 in Paris, accurate copies of which are in all 

 the national archives and the length of 

 which is known in terms of the wave-length 

 of light, or shall we continue to use as our 

 unit a broken brass rod riveted in the mid- 

 dle which differs from everything else in 

 creation. 



Compound numbers, which to the French 

 are known in ancient history, are to us a 

 daily nuisance. They take up a good third 

 of our arithmetics, by far the hardest third 

 at that, and require about a year of a 

 child's school life to learn even passably. 

 If the 'English accountant' can add guineas, 

 pounds, shillings, pence and farthings as 

 rapidly as an American accountant can add 

 dollars and cents, it must be because the 

 greater difficulty of his- task has caused a 

 greater mental development. If Sir Fred- 

 erick Bramwell can calculate by mental 

 arithmetic how many grains of water there 

 are in a gallon as quickly as a child can 

 tell how many grams there are in a liter he 

 is indeed a mathematician. 



The requirements of scientific work are 

 not so different from those of commerce as 

 has been imagined. It is not a matter of 

 indifference to the scientist whether his 

 measures are capable of easy division. A 

 chemist has to make more divisions into 

 aliquot parts than a shopkeeper, as I know 

 by personal experience in both capacities. 



It is probable that the duodecimal nota- 

 tion would be preferable to the decimal, 

 though it is not certain that it is the best 

 that could be devised. Notations based on 

 eight, sixteen and two have, I believe, been 



more favored by mathematicians than that 

 based on twelve. The difficulties of a 

 change are, however, almost inconceivable,, 

 perhaps as great as a change to a more 

 perfect language would be, and it seems 

 hardly worth while to take into considera- 

 tion its possibility. The fact is that for the 

 period intervening between that geological 

 epoch when our saurian ancestor lost his 

 sixth digit, to that perhaps equally remote 

 date when men shall become intelligent 

 enough to choose a better system of nota- 

 tion than the present, the world is doomed 

 to a decimal system. Let us then make the 

 best of it by bringing weights and measures 

 in accordance with it and, instead of com- 

 plaining, rather be thankful that the first 

 human arithmetician had five fingers in- 

 stead of seven, since he did not have the 

 happy medium. It seems that the English, 

 in spite of their national genius for devising 

 incommensurable units, are moving as fast 

 in the matter of adopting a better system of 

 weights and measures as the Americans, 

 and we may put faith even in the prophecy 

 made by Matthew Arnold in one of his 

 optimistic moods, that the time will yet 

 come in England when the fact that an in- 

 stitution is an anomaly will be regarded as 

 an objection, not an advantage. 



E. E. Slosson. 

 University of Wyoming. 



THE USE OF THE HAIB HYGROMETER. 



Fob some time past there has been an in- 

 creasing demand for a direct reading hy- 

 grometer, so constructed that it would in- 

 dicate the relative humidity of the air with 

 reasonable accuracy. 



Among those hygrometers which have 

 been considered as possibly suitable for 

 this purpose is the Saussure's or hair hy- 

 grometer. Although formerly this hygrom- 

 eter was looked upon merely as a hygro- 

 scope, and was supposed to give only the 

 approximate hygrometric state of the air, 



