In this connection should be mentioned that self-sealing fruit jar, known from its inventor as “Mason’s fruit jar,” which came into such universal use--that combination of screw cap, screw-threaded jar-neck and the rubber ring, or gasket, on which the cap was screwed so tightly as to seal the jar hermetically. In lamplighting, what a wonderful change from the old oil lamps of former ages! The modern lamp may be said to be an improved means of grace, as it will hold out much longer, and shed a far more attractive light for the sinner, whose return, by its genial light, is, even to the end, so greatly desired. The discovery of petroleum and its introduction as a light produced a revolution in the construction of lamps. Wicks were not discarded, but changed in shape from round to flat, and owing to the coarseness and disagreeable odour of coal oil, especially in its early unrefined days, devices first had for their object the easy feeding of the wick, and perfect combustion. To this end the burner portion through which the wick passed was perforated at its base to create a proper draft, and later the cap over the base was also perforated. But with refined oil the disagreeable odour continued. It was found that this was mainly due to the fact that both in lamps and stoves the oil would ooze out of the wick on to the adjacent parts of the lamps or stove, and when the wick was lit the heat would burn or heat the oil and thus produce the odour. Inventors therefore contrived to separate the oil reservoir and wick part when the lamp or stove were not in use; and finally, in stoves, to dispense with the wick altogether. As wickless oil stoves are now in successful use the wickless lamp may be expected to follow. The lamp, however, that throws all others into the shade is that odourless, heatless, magic, mellow, tempered light of electricity, that springs out from the little filament, in its hermetically sealed glass cage, and shines with unsurpassed loveliness on all those fortunate enough to possess it. CHAPTER XXIII. LEATHER. It is interesting to speculate how prehistoric man came to use the skin of the beasts of the field for warmth and shelter. Originally no doubt, and for untold centuries, the use was confined to the hairy, undressed, fresh, or dried skins, known as pelts. Then came the use of better tools. The garments have perished, but the tools of stone and of bronze survived, which, when compared with those employed among the earliest historic tribes of men, were found to be adapted to cut and strip the hairy covering from the bodies of animals, and clean, pound, scrape and otherwise adapt them to use.