"According to native testimony, the male ostrich sits on the nest (which is merely a hollow place scooped out in the sand) during the night, the better to defend the eggs from jackals and other nocturnal plunderers. Towards morning, he _brummels_, or utters a grumbling sound, for the female to come and take his place; and she sits on the eggs during the cool of the morning and evening. In the middle of the day, the pair, leaving the eggs in charge of the sun, and 'forgetting that the foot may crush them, or the wild beast break them,' employ themselves in feeding off the tops of bushes in the plain near the nest. Looking aloft at this time of day, a white Egyptian vulture may be seen, soaring in mid-air, with a large stone between his talons. Having carefully surveyed the ground below him, he suddenly lets fall the stone, and then follows it in rapid descent. Let the hunter run to the spot, and he will find a nest of, probably, a score of eggs, (each equal in size to twenty-four hen's eggs,) some of them broken by the vulture. The jackal, too, is said to roll the eggs together to break them; and the hyæna pushes them off with his nose, to bury them at a distance." ------------------ FIRE-PROOF HOUSE ON PUTNEY HEATH. Upon Putney Heath, by the road-side, stands an obelisk, to record the success of a discovery made in the last century, of the means of building a house which no ordinary application of ignited combustibles could be made to consume. The inventor was Mr. David Hartley, to whom the House of Commons voted 2,500_l._, to defray the expenses of the experimental building, which stood about one hundred yards from the obelisk. In 1774, King George the Third and Queen Charlotte took their breakfast in one of the rooms; while in the apartment beneath, fires were lighted on the floor, and various inflammable materials were ignited, to attest that the rooms above were fire-proof. Hartley's secret lay in the floors being double, and there being interposed between the two boards sheets of laminated iron and copper, not thicker than tinfoil or stout paper, which rendered the floor air-tight, and thereby intercepted the ascent of the heated air; so that, although the inferior boards were actually charred, the metal prevented the combustion taking place in the upper flooring. Another experiment took place on the 110th anniversary of the great fire of London, when a patriotic lord mayor and the corporation of London witnessed the indestructible property of the structure. Yet, the invention was never carried into further practice. The house was, many years after, converted into a tasteful villa, although the obelisk records the success of the experiment. ------------------ THE LAST OF THE ALCHEMISTS.