# Page:Popular Science Monthly Volume 80.djvu/444

time and of careful work. We are at present engaged not only in checking this value under new sets of conditions, but in redetermining all of the quantities which enter into it. Assuming it as the basis of our computation there are in a cubic centimeter of gas under normal conditions ${\displaystyle 2.70\times 10^{19}}$ molecules and the weight of a hydrogen atom is ${\displaystyle 1.735\times 10^{-24}-grams}$. These numbers can be made more significant to the ordinary reader with the aid of an illustration. If a million men were to be set counting as fast as they could count, say at the rate of 200 a minute, they could count out the number of molecules in a cubic centimeter in just 252 thousand years if none of them ever stopped to eat, sleep, or die.