280 



THE POPULAR SCIENCE MONTHLY. 



Mr. Im Thurn had observed no animal life 

 while he was upon the mountain ; Mr. Dies- 

 sel saw a few butterflies, all of a dark-brown 

 and nearly black color. In the shallow ba- 

 sins a few specimens of a small black toad 

 with a yellow spot on the throat were found. 

 A third animal form was noticed in the 

 moist earth attached to some plants which 

 had been pulled up a milliped. The fan- 

 tastic shapes into which the sandstones have 

 been formed, and the calmness of the scene, 

 affected Mr. Dressel as they had Mr. Im 

 Thurn. 



Experience and Training in Mechanical 

 Work. To be a good mechanic, said Sir 

 Benjamin Browne, at the recent meeting of 

 the British Association, long training is neces- 

 sary; and, above all, ability to distinguish 

 good work from inferior work. A regular 

 course of progress from one branch to an- 

 other should be carefully followed, so as to 

 teach every class of work up to the most dif- 

 ficult. In this the real interest of the em- 

 ployer is the same as that of the lad, viz., to 

 learn every step thoroughly, and then pass 

 on to something more difficult. The author 

 contended that a long training in a manu- 

 factory is absolutely necessary, and this 

 should be supplemented by theoretical and 

 technical instruction. It would probably be 

 a great gain to give a lad six or eight 

 months of theoretical teaching after he is out 

 of his apprenticeship. The old-fashioned 

 system of apprenticeship, not much short- 

 ened, and with very slight modifications, is 

 the only reliable method for cither employer 

 or mechanic to learn his business ; but, as 

 work has become more scientific and elabo- 

 rate, it is necessary for any young man who 

 wishes to excel to have a good theoretical 

 and technical training in addition to his fac- 

 tory experience. 



How Stone Implements were made. 



Mr. Gerard Fowke, of Sidney, Ohio, has been 

 studying the manner in which primitive man 

 made his stone implements. Although the 

 subject is one on which absolute knowledge 

 can never be obtained, he has been able to 

 reach some definite conclusions on it. Some 

 of the material was obtained from extensive 

 quarries in Coshocton County, and between 

 Newark and Zanesville, Ohio, where the hills 



are seamed for miles with the trenches and 

 pits left by the ancient diggers. To get the 

 flint, the overlying stratum of earth, nine or 

 ten feet thick, had to be removed, with 

 wooden tools. The rock was then cracked 

 by building a fire, and probably pouring 

 water upon it, the process being repeated 

 till the limestone was reached and a hole 

 made large enough to work in. Other cracks 

 were made by building a fire at the lower 

 part of the ledge, and the split rock was de- 

 tached. This work was sometimes carried 

 on for several hundred yards. The stones 

 were reduced to blocks of suitable size by 

 stone hammers weighing, perhaps, two hun- 

 dred pounds, and the shaping was carried on 

 with hammers running, according to its stage 

 and the quality of work desired, down to two 

 ounces in weight. The finished object was 

 smoothed and sharpened by rubbing it with 

 sandstones. If a hole was wanted, it was 

 drilled with a stick, cane-stem, piece of bone 

 or horn, flint, or piece of sandstone, which 

 was revolved in the hands, or twisted back 

 and forth with the bowstring. This was 

 not a speedy process. Dr. Bau worked at 

 it experimentally for two years, and left his 

 first hole not bored through. Yet some of 

 the Amazon tribes spend the lifetimes of two 

 men in drilling, with the flexible shoot of a 

 wild plantain and sand and water, the bores 

 of their tubes of rock crystal. Handles 

 were fitted on in a rude way and secured by 

 wrapping with sinew, which shrunk and 

 bound them tightly ; or, with the aid of gum. 

 The fashioning of arrow- heads was a very 

 delicate and curious work, requiring skillful 

 manipulation, and was performed with stone 

 hammers or chisel-points of deer-horn or 

 wood. 



Bellito. The new explosive, bellite, was 

 recently subjected in England to some very 

 satisfactory tests of its safety and power. 

 Letting a great weight fall upon cartridges 

 composed of it, they were simply crushed 

 into a hard mass. But when the crushed car- 

 tridges were afterward detonated by means of 

 a fulminate, immense energy was developed. 

 Again, when placed in the fire of a smith's 

 forge, it was volatilized. The effect of ex- 

 ploding a three-ounce cartridge on the lid 

 of a case containing bellite was simply to 

 pulverize the wooden case and scatter the 



