256 



SCIENCE 



[Vol. XVII. No. 431 



la maitre is half-way in, one shuts, and when all the way in, the 

 other closes, leaving the master of the house as isolated and ex- 

 clusive as Robinson Crusoe on his desert island. One of these 

 " viper shells," brought from California lately, was so thoroughly 

 sun-baked and hardened that though more than two feet long it 

 could be dropped on the floor without breaking. 



— A "security" elevator soon to be introduced is described as 

 follows by a member of the Polytechnic Society of Kentucky : 

 The framework of its hatchway is supplied, at each of the two 

 sides or ends which stand at right angles to the cage entrance, 

 ■with a pair of wood studs extending from the bottom to the top 

 of the hatchway, and with a space of seven-eighths of an inch be- 

 tween them. Into one of each pair of these studs is caseniented 

 a series of horizontally arranged steel bolts ten, or it may be 

 twelve, inches apart. These bolts are movable, and when pushed 

 seven-eighths of an inch outward their ends project across the 

 spaces between the studs; and as long as they remain thus across, 

 nothing, of course, can pass up or down within these spaces. 

 When, however, they are drawn back into their casements, the 

 spaces are vacant, and any thing can ascend or descend through 

 them. The framework of the cage is constructed on a central 

 wrought iron beam, the ends of which project into these spaces. 

 When the cage is at the bottom of the hatchway, the bolts are 

 within their casements; but the in.stant its central beam passes 

 the two bolts next to it, these, by its movement upwards, and 

 through a device which is as immediate as it is simple and 

 positive, are projected out of their casements across the spaces 

 underneath the beam. When the conductor has reached any 

 point at which he wishes to descend, he lays one of his hands 

 against a button and through a continued pressure brings into 

 action a device similar in nature to the one which, through the 

 movement of the cage upward, pushed the bolts out across those 

 spaces, and through the movement of the cage downwan) each 

 successive pair of bolts next underneath are drawn back into their 

 casements. Various ingenious devices are introduced to avoid 

 the chance of accidental pressure on the button. 



— The separation of magnetic iron-ore from the rock with which 

 it is associated, savs Engineering, has often been attempted with 

 more or less success. Even if only a part of the rock is eliminated, 

 there is a substantial gain, particularly in cases where the ore has 

 to be transported long distances from the mine to the blast fur- 

 nace. But if the gangue contain phosphorus or sulphur, as it 

 often does, so long as any appreciable amount of it remains, the 

 iron made from the ore is unfitted for use in the Bessemer proc- 

 ess, and. sells at a lower price than it would if it had been freed 

 from these impurities. It has therefore been the object of 

 inventors to produce a separator which would remove the rock so 

 effectually that not more than .05 per cent of phosphorus should 

 remain, even when the iron is associated with a gangue of phos- 

 phate of lime. The difficulty found was, that immediately the 

 ptdverized ore was magnetized all the particles clung together, 

 entangling between them fragments of rock, which could only 

 escape with difficulty, if at all. Various means were tried by 

 vibration and alternate magnetization and demagnetization to per- 

 mit the rocky particles to get away from the embrace of the metal. 

 Whatever measure of success might be attained in this way, and 

 the results were far from being fully satisfactory, it did not extend 

 to the case of particles formed partly of iron and partly of rock. 

 These were attracted by the magnet and remained with the metal. 

 In the Monarch magnetic ore separator, however, invented by 

 Messrs. Ball and Norton, a very ingenious method has been de- 

 vised of freeing the rocky particles, and of discriminating between 

 those that are entirely metallic, and partly metallic and partly 

 earthy. The crushed ore is fed on to the surfacei'Of a rotating 

 paper drum. Within this drum, and occupying less than half its 

 circumference, is a multipolar magnet, having twelve poles 

 alternately north and south. Immediately the metallic particles 

 touch the drum they become polarized, and hang on by one end. 

 In passing from the first pole to the second of the stationary mag- 

 net the opposite pole of each particle is attracted, while that hith- 

 erto attracted becomes repelled. Consequently the fragment turns 

 end for end, and in so doing any rock clinging to it has the chance 



to escape downwards under the action of gravity. This effect is 

 repeated some twelve times. After passing half way round one 

 drum the ore is delivered on to a second, running at a higher 

 speed, and here centrifugal force aids the separation. The same 

 process of turning over the fragments is repeated, and should any 

 of them happen to be partly of rock and partly of iron they are 

 sui-e to be thrown off and eliminated. The final product is 

 almost entirely of icon, the phosphorus being reduced to .05 per 

 cent. 



— "It is, I think, well to record the following observations of 

 the intelligence of the thrush," says John Hoskyns-Abrahall in a 

 letter to Nature of April 23. "The first happened on June 28, 

 1865. I then saw, from the windows that look out on the little 

 lawn north of my house, a thrush steadily ' stepping westward ' in 

 front of the hedge that parts the lawn from the public road. The 

 bird seemed to be intentionally making for a gravel path that, 

 after passing almost close to the windows, bends to the north-west, 

 toward the small gate of my front garden. It was bearing some- 

 thing in its bill. On coming to the path it attempted to break 

 this on a stone. It did not succeed. It then tried another stone. 

 This time it succeeded. Thereupon it flew away. On the spot I 

 found a remarkably big stone embedded in the path, and round it 

 were scattered bits of snail shell. The bird had eaten the snail. 

 The second of the observations I would note, and the more striking 

 of the two, happened on June 5, 1890. I then was viewing the 

 gravel path from the westernmost of the four windows. Just be- 

 neath me, standmg on the path, was a female thrush. She had 

 succeeded in breaking a snail shell. She had the snail in her bill. 

 But, despite of vigorous efforts, she could not swallow it. Up 

 hopped a male thrush. Standing before the female, he opened 

 his bill. She dropped the snail into his bill. He chewed the snail. 

 He dropped it back into the female's ready bill. She swallowed 

 it. The pair blithely trotted off, side by side, toward the small 

 gate. I saw them no more." 



— Mr. W. H. Goodyear, writing to the New York Nation from 

 Keneh, Upper Egypt, on March 17, says that Mr. Petrie has un- 

 earthed at Maydoom " the oldest known Egyptian temple and the 

 only Pyramid femple ever found.'' Apart from the Temple of 

 the Sphinx at Ghizeh. this buililing is also •' the only temple of 

 the Old Empire so far known." It was buried under about forty 

 feet of rubbish. It lies directly at the centre of the eastern base 

 of the Pyramid, on the side facing which it has two round-topped 

 obelisks. •' Obelisks and temple chambers so far entered," says 

 Mr. Goodyear, "have the plain, undecorated style of the Old 

 Empire, as shown by the Temple of the Sphinx, but hieratic in- 

 scriptions in black paint found within fix the name of Seneferoo 

 as builder, and confirm the supposition to this effect hitherto based 

 on the fact that tombs near the Pyramid contain his cartouche. 

 Seneferoo is the king connecting the third and fourth dynasties, 

 and variously placed in either. According to computations of 

 Mariette and Brugsch, the antiquity will be about 4000 B.C., or 

 earlier." On Tuesday, March 10, Mr. Petrie's workmen reached 

 a platform which appeared to be a causeway terminating with 

 two obelisks at the base of the Pyramid. "In the forenoon of 

 Wednesday,'' continues Mr. Goodyear, "a workman came to say 

 that an opening had been found under the platform on the side 

 next the Pyramid. This proved to be the top of a doorway 

 choked by detritus, through which Mr. Petrie crawled into an in- 

 terior of three chambers and discovered the inscriptions men- 

 tioned. I had the pleasure of following him. Mr. Petrie thought 

 the apartments had not been previously entered for about three 

 thousand years — that is to say, that the rubbish fallen from the 

 pyramid had choked the entrance about three thousand years after 

 construction. A friend who was with me noticed on the floor 

 some dried wisps of papyrus, a plant now extinct in Egypt. The 

 chambers thus far found are so filled that one cannot stand erect 

 in them, and a door at the end of the third chamber is blocked 

 by large stones. Over all lies an enormous mass of detritus, whose 

 removal by Arab diggers is now in progress. I had the pleasure 

 next day of carrying the news of Mr. Petrie's find to the gentlemen 

 of the Egypt Exploration Fund at Beni-Hassan, and of witnessing 

 their unaffected delight over it." 



