Page:Popular Science Monthly Volume 29.djvu/407

Rh little or no aptitude. All minds can not be compressed into an identical mold without doing serious injury to some individual brains. A child with keen perceptive faculties and good reasoning powers is capable of growth in some directions, much more rapidly and with far greater pleasure to itself than in others.

Finally, I would suggest that parents study with care and anxiety the mental and physical traits of their offspring. Allow neither to detract from the other. Pick out for each child the line of development for which Nature seems to have furnished the best material, and the result will conduce to the future success of the child and the ultimate happiness of the parents.



F the many methods in use for the protection of iron from rust, the one of most scientific interest is the so-called Bower-Barff process. By this treatment the iron is coated with a layer of the black or magnetic oxide of iron (Fe3O4), and, as is well known, this oxide does not undergo any further oxidation on exposure to air or water—proved by the magnetic iron-ores and sands, which withstand any amount of weathering. The liability of iron to rust is a great drawback to its use for many purposes, and the practical value of a process which will protect it, at a slight expense, is self-evident. That the process is successful in accomplishing this object seems no longer a matter of doubt, and at less cost than galvanizing or tinning. The color on cast and wrought iron is a bluish-gray, which to some may be objectionable, but, as the coating takes paint far better than untreated iron, this objection is easily overcome, and with the assurance that the paint will remain, and not soon be thrown off as it is generally. For polished work the color is a lustrous blue-black, adding greatly to the beauty of the article treated. This process seems peculiarly well adapted for gas and water pipes. Any one who has had occasion to use water which has passed through a new iron pipe, or one that has not been used for some time, knows how full of rust it is, and that only after months of constant use does it become clear again. With pipe coated with the magnetic oxide by the Bower-Barff process, no trouble of the kind can occur. The water runs pure from the first day, and if for any reason the pipes are emptied, and left so, there is no danger of their becoming coated with rust. Another important fact is, that the water coming through one of these rustless pipes is just as pure as when it entered, for the water can dissolve none of the coating of oxide, as it always does with lead or galvanized pipes. It is a well-known fact that water running through lead pipes is very apt to 