Page:Popular Science Monthly Volume 45.djvu/509

 enough, heat to change sixty-eight pounds of water by one degree Centigrade. To cool the cubic mile of air formerly considered sufficiently to make a rainfall of a quarter of an inch would accordingly take four hundred and six million pounds of carbonic acid. This could probably be purchased in quantities of this magnitude at one dollar a pound, making the expense of a rainfall of a quarter of an inch, not counting anything but the carbonic acid, about six hundred thousand dollars per acre. This would make artificial climate even more expensive than the genuine California article.

I have now endeavored to give you in as brief a space as possible a simple statement of the problem of rain-making as it appears to one with an elementary knowledge of physics, and to give a brief statement of some of the methods of the men who, without any scientific knowledge, have intentionally or unintentionally imposed upon the public. The examples which I have quoted are only the prominent ones. There are many impostors whose names are but little known who are proposing to furnish rain to large sections of country for a suitable financial consideration. And it is only surprising that the number is not larger. The business offers special inducements to men who are accustomed to make a living by swindling their fellow-men. No capital and no business training is required. The only thing necessary is to contract to furnish rain to as many different sections of country as possible. Then, if it rains over any of these areas, collect the pay. If it does not rain, the experiment has cost nothing. The system has all the advantages of the traditional gun loaded to kill if it is a deer, but to miss if it is a calf.



N the natural advance made in the study of the subject of infant foods—methods of preparation, administration, etc.—the process of sterilization of milk, as ordinarily and formerly understood, is now replaced by "Pasteurization," which is, practically speaking, the low-temperature process of the earlier method, and specialists who comprehended the serious changes produced in milk by high and prolonged temperature advised from the first the lower method.

It is easy enough, by prolonged and repeated application of a high temperature, to keep milk apparently unchanged, but the point aimed at all along has been to devise a way by which it might be made sterile with the least possible interference with