370 



SCIENCE 



[Vol. XV. No. 385 



monial dances were held: and near by was the creek in 

 wliich the ablutions were performed. The council-house in 

 this case was not in the village; the latter being built near 

 the hills, contiguous to cool springs of water, thus rendering 

 the distance from it to the creek too great for the conven- 

 ience of the bathers. The writer is aware that this expla- 

 nation will not apply in full to all the enclosures of this 

 type, as the conditions are not the same in all the localities; 

 and it is more than likely that the customs of the villages 

 varied to some extent, although pertaining to the same 

 tribe. The probable differences in the age of the villages, 

 and the modifications of customs, are also to be taken into 

 consideration ; nevertheless this supposition gives us a key 

 that will unlock most of the mystery of these works. They 

 are in most cases located near a stream, and consist of a 

 square or octagon with its gateways and protecting mounds 

 surrounding the village, and a circle enclosing the corn-field. 

 As a rule, the small circles, which may have been places of 

 amusement and ceremony, are outside of the large enclos- 

 ures. Even at Fort Ancient, which no one doubts is a de- 

 fensive work, the supposed race-track and principal mounds 

 are outside, though the crescent, in front of which the cere- 

 monial rites were performed, is within the fort. 



[Continued on p. 372.] 



NOTES AND NEWS. 



Some curious electrical phenomena were observed, according 

 to a writer in the Chemische Zeitmig, in a stearin and ceresin 

 manufactory in Italy. One evening four vats of white ceresin 

 (which is a paraifine obtained from ozokerite) containing about 

 500 kilograms each, were being stirred to cool. When the point 

 of solidification was nearly reached, the electric light of the place 

 accidentally went out; and. to the surprise and alarm of the rather 

 ignorant workmen, the mass of ceresin was observed to give pale 

 sparks on the slightest motion. If the hand was brought near, 

 loud sparks nearly two inches long were ot>tained. The phenom- 

 enon lasted over half an hour. 



— Some interesting explorations have been made in connection 

 with the famous Adelsberg Cave. The Vienna correspondent of 

 the London Daily News says that various citizens of Adelsberg, 

 wishing to ascertain whether the Ottoker Cave, discovered a year 

 ago at some distance from Adelsberg, was in any way connected 

 with the great cave, followed the course of the subterranean river 

 Poik. It was known that forty years ago a patty of explorers 

 had their progress barred by a large lake, and the present adven- 

 turers therefore carried with them a boat. Having successfully 

 crossed the body of water mentioned, they came to lofty galleries 

 through which the river flowed. It was possible to walk on the 

 banks of the stream, but at intervals it expanded into small lakes, 

 and the boat had to be used. At last the gallery branched into 

 two corridors, one of which the stream rendered impassable, 

 while the other was high and quite dry. The boat was dragged 

 up, and the party proceeded. After crossing a fourth lake, the 

 largest they had met, they found that the Ottoker Cave had been 

 reached. The journey througli the galleries lasted six hours. 

 The explorers saw that they had by no means penetrated to the 

 remotest parts of the grotto, and there is evidently still a wide 

 field for discovery. 



— We learn from Engineering of May 30 that the Chatillon- 

 Commentry Steel Company have for some time past been experi- 

 menting with gim-tubes, projectiles, and armor-plates of steel 

 tempered in lead. The process is simple, the steel being raised to 

 a red heat and then plunged in a bath of molten lead, where it is 

 allowed to cool gradually. The beneficial effects of this treatment 

 are very marked, the elastic limit, breaking stress, and percentage 

 elongation of the material being all increased. Actual tests of an 



armor plate thus tempered, 10 8 inches thick, which was tested 

 at St. Jacques by firing at it with a 3.75-inch gun. showed that 

 the penetration in the tempered plate was much less than in art 

 untempered one. The value of this test is, however, somewhat 

 discounted by the fact that the power of the gun was much be- 

 low that required for penetrating the plate, as the striking velocity 

 of the shell was only 1,300 feet per second, and its penetration in 

 wrought iron would therefore be only about 4.85 inches. 



— At the instance of Professor Otto Pettersson of Stockholm, a. 

 hydrographic expedition has been arranged ; the professor himself 

 and Baron Oscar Dickson finding the necessary funds, with some 

 assistance from two Swedish marine insurance companies. Ther 

 expedition, which will start from Gothenburg, comprises the sal- 

 vage steamer "Skandinavien," the gunboat "Alphild," the pilot 

 steamer "Goteborg," and the two steamers "Themis" and "Iris."' 

 Men of science will be found on board all these steamers, and 

 samples of water and measurements of temperature will be taken. 

 The Skagerak and the Kattegat, which are to be the places of 

 operation, have been divided into different sections. The appli- 

 ances were tested at Stockholm the other day, says Engineering 

 of May 30, and gave great satisfaction. They compi-ise an appa- 

 ratus constructed by Professor Ekman for bringing up water 

 from a depth of up to three hundred feet, furnished with a 

 warmth-isolator; a turbine apparatus by the same gentleman for 

 bringing up samples of water from any depth, and fitted with 

 one of Negretti and Zambra's deep-water thermometers; and sev- 

 eral appliances for similar purposes constructed by Commander 

 Arwidsson, very quick in their mode of operating, but not in- 

 tended for any great depth nor for very large samples. 



— Some sea urchins are known to live in cavities in rock; and. 

 the diameter of the cavity is often wider than that of the en- 

 trance, so that the animal could not leave its home or be taken 

 out without injury. On the French coast of Croisic (Lower 

 Loire) may be seen thousands of urchins thus ensconced in the- 

 granite rock, which is rich in felspar and quartz. The animals, 

 it is not doubted, make and widen the holes for themselves; but 

 the question how has not been satisfactorily answered. Chemical 

 solution of the rock seems excluded, considering both the nature 

 of the latter, and also that no acid which could be thus used has 

 been proved to exist in the urchin. The matter has been studied 

 lately by M. John, and in an inaugural dissertation he explains, 

 the effects by mechanical action. With the so-called "lantern of 

 Aristotle," as given in Nature of May 29, the animal probably 

 bites the rock. The sucker feet are also attached, and a rotatory 

 motion is imparted to the body ; the prickle points, with the lan- 

 tern, gradually wearing down the surface. These cavities afford 

 a shelter to the urchins against the action of the waves. An at- 

 tempt is made to conceal them by means of mussel and other 

 shells. The rocks in which the cavities occur are in general 

 thickly covered with calcareous algse. It has been thought that 

 possibly these decompose the rock, and so facilitate the work of 

 the urchins. M. John, however, finds no such chemical relation; 

 but atmospheric agencies, he considers, may help the work of 

 boring. A number of other animals are known to penetrate rock, 

 and it is supposed that they do it also in a mechanical way. M. 

 Forel described to the Vaudois Society of Natural Sciences how, in 

 the hard limestone of Constantine, Algiers, Helix aspera was 

 found in holes four to five inches in depth. 



— It was natural to suppose, that, as heat weakens the strengtb 

 of a steel magnet, the susceptibility of a magnetic substance would 

 increase with a fall of temperature, as also that bodies vchich in 

 ordinary thermal conditions are neutral to magnetic influence,, 

 would exhibit magnetic properties if cooled down sufficiently.. 

 This point, says Engineering of May 2, was dwelt upon by Dr.- 

 Hopkinson in his remarkable address to the Society of Electrical 

 Engineers, and was also made the subject of experimental demon- 

 stration by Mr. Shelf ord Bid well in his recent discourse on mag- 

 netic phenomena at the Royal Institution. The substance used 

 was an alloy of nickel and iron. Both these metals are magnetic; 

 at ordinary temperatures, but the alloy is perfectly neutral. A 

 permanent magnet is unable to lift a strip of it; but, if cooled a 

 few degrees below zero, the strip is at once strongly attracted by 



