Page:Popular Science Monthly Volume 90.djvu/437

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Popular Science Monthly


��this or any other country. Had it been allowed to remain at rest after the disease had shown itself in the great crack extend- ing about two-thirds of the distance from the lip to the top, being stopped by the somewhat thicker metal of the word "Philadelphia," as shown in the illustra- tion, the new and more dangerous crack running diagonally around the Bell from the letter "P" in Philadelphia to beyond the letter "Y" in "Liberty" would probably not have occurred. It was not observed until after the bell had made a number of journeys over the country-.

It is not at all astonishing, therefore, that our venerable Liberty Bell, having passed through the melting pot three times, and having been doctored by amateurs in metals, should still have symptoms of its old disease.

Steel, too, becomes fatigued after long usage and loses its strength. This is par- ticularly true of steel parts that are sub- ject to frequent vibrations and shocks. In time the metal changes, its crystalline form alters and it becomes diseased or rotten, and breaks. This is especially true of poorly made steel, but it is also true of some of the best.

Modern metallurg\- has discovered cer- tain elements similar to a tonic which can be added to steel, which offset the tendency to fatigue. One of these is vanadium. When only 1/20 of one per cent is put into steel, the metal becomes so benefited that it is called anti-fatigue steel.

��Transplanting Palm Trees Without Sacrificing Their Foliage

IT is almost impossible for even a lettuce slip to be removed from the spot where it has taken root without a consequent drooping and period of suspended growth. But nowadays, great palm trees are up- rooted and carried hundreds of miles from their native soil and climate with scarcely a wilted leaf.

The secret of the success of transplanting such trees lies in the preliminary work. This is begun fully six months before the time for the moving of the tree. First the roots are dug around and carefully cut, and the plant is side-boxed. Three inches are allowed between the balls of roots and the boxing. This space is next filled with earth, which is well tamped down. Thus the tree is made to stand in the box in w*hich it is to be moved, without lifting it from the ground. Here it remains during the six months of preparation. It is thoroughly mulched and given the best of care so as to induce a^plentiful side growth of roots. At the end of the six months it may be lifted and shipped. It will show no signs of fatigue at the end of its journey, how- ever far it may travel.

���The palm is lifted and shipped without disturbing the roots, for they have been growing in the shipping box for six months in the richest mulch to prepare them for the journey

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