24: 



NATURE 



\7nly 15, 18S0 



all in the room. We found the tumbler shattered into fragments, 

 the body of the glass ripped up, as it were, into several large, 

 irregular-curved )>ieces, and the bottom of the tumbler broken 

 into small pieces more resembling thick rough ice than anything 

 else. Query : Was the explosion caused by the inherent 

 properties of the toughened glass, or by the contact of potash, 

 soda, the silver spoon, and proximity to a lamp, the heat from 

 which was very slight, indeed scarcely perceptible to the hand at 

 the spot where the tumbler stood ? 



The accident might have been very serious, for pieces of the 

 glass flew to within a very few inches of the lady's face. A 

 solution of the cause of the explosion is therefore of considerable 

 importance to all who may have occasion to use vessels of this 

 peculiar glass. NoBLE Taylor 



Sunninghill, July 7 



Great Meteor 



A METEOR of extraordinary brilliancy was seen on Friday, 

 July 9, about 8*20 p.m. — almost in full daylight, the sun having 

 only just set — by the Rev. Mr. Lbyd-Jones, who kindly took me to 

 the place of observation and gave me the following particulars : — 



The meteor was quite half as large as the full moon, of dazzling 

 light-blue colour. It moved slowly in a path inclined about 10° 

 to the horizon, from left to right, and emitted a train of ruddy 

 sparks. Mr. Lloyd-Jones was looking in the opposite direction, 

 and had time, after his attention was called to it by a friend, ta 

 turn round and see the last 10° of the path. The total duration 

 may have been ten seconds, and could not have been less than 

 five, the meteor dying out slowly. The point of disappearance 

 was carefully noted and referred to some trees about 200 yards 

 distant. I afterwards found it to be in true azimuth N. 69!° E., 

 altitude 9'. No detonation was heard. The place of observa- 

 tion was about two-thirds of a mile east of the Royal Observa- 

 tory, Greenwich. G. L. Tupman 



Iron and Hydrogen 



May I be allowed to point out that the question of the 

 occlusion of hydrogen in steel, and its influence in hardening, 

 has been discussed by Mr. Wm. Anderson in his report to the 

 Committee of this Institution on the Hardening, &c., of steel. 



At the last meeting of this Institution Prof. Hughes stated 

 that his experiments did not support the hydrogen theory, but 

 rather the view that hardened steel was an actual alloy of carbun 

 and iron, unhardened steel a mixture only. I may add that 

 experiments are now in progress, designed to test the truth of 

 this latter view. Walter R. Browne 



Secretary 



Institution of Mechanical Engineers, July 12 



The Stone in the Nest of the Swallow 



The swallow stone is the agate pebble, called in French 

 chikdoine — the name given to the chalcedony (Nature, vol. xxi. 

 p. 494), but the same virtue is attributed to the swallow herb. 

 This is the ChcliJonium majus, about which Britten and 

 Holland, in their " English Plant Names," give the fallowing 

 quotation from Lyte : — " Chelidonium, that is to say, swallow- 

 herbe, bycau-e (as Plhiie writeth) it was first found out by 

 swallowes and hath healed the eyes and restored sight to their 

 young ones that had harme in their eyes or have bene blinde." 



Littre, in his great Diclionnaire, gives two quotations, in 

 which Chckdoinc is used in a botanical sense : — 



" Se vus avez as oils manjue 

 Dune prenez celedoine et rue." 



MS. St. Jean, \T,th ceniury. 



" Aussi les guerit le jus de cheledome, le lait de tithymal."— 

 Pare, Z). 21, i5.'/^ century. 



He also gives its meaning as the name of a precious stone, and 

 adds: " Petits cailloux appartenant aux agates, on dit aussi 

 pierres d'hirondelle." With respect to its etymology he says 

 he derives it from "xeAiSwioi-, de xf^'5'i"', hirondelle, .a cause 

 qu on disait que I'hirondelle se servait de cette plante pour rendre 

 la vue a ses petits." William E. A. Axon 



i-ern Bank, Higher Broughton, Manchester 



THE CARIBBEAN SEA 



'T'HE Coast Survey steamer Blake, Commander J. R. 

 -*■ Bartlett, U.S.N. , Assistant Coast Survey, recently 

 returned from a ci-uise taking soundings, serial tempera- 

 tures, 5:c., in the course of the Gulf Stream, under in- 

 structions from C. P. Patterson, Superintendent Coast 

 and Geodetic Survey, has brought very interesting data 

 in regard to the depths of the western portion of the 

 Caribbean Sea. 



The depths and temperatures obtained last year in the 

 "Windward Passage" between Cuba and San Domingo 

 were verified, and a few hauls of the dredge taken 

 directly on the ridge in this passage. The data obtained 

 render it very probable that a large portion of the supply 

 for the Gulf Stream passes through this passage, and 

 that the current extends in it to the depth of Soo fathoms. 

 A few lines of soundings with serial temperatures were 

 run from Jamaica to Honduras Bank, vid Pedro and 

 Rosalind Banks, and it was found that the temperature 

 of 39j°. obtained at .all depths below 700 fathoms in the 

 Gulf of Mexico and the Western Caribbean, could not 

 enter through this portion of the sea. But the tempera- 

 ture at the depth of 800 fathoms on the ridge in the 

 "Windward Passage" between Cuba and Hayti was 

 found to agree with the normal temperature of the Carib- 

 bean and Gulf of Mexico, viz., 39j°. Soundings were 

 taken between Hayti and Jamaica, developing a general 

 depth between 'these islands not exceeding Soo fathoms, 

 except where broken by a remarkably deep channel con- 

 necting the waters of the main Caribbean south of San 

 Domingo with those north of Jamaica. This channel 

 runs close to Hayti with a greatest depth of 1,200 fathoms, 

 and a general depth of 1,000 fathoms. Its course is 

 northerly along the western end of Hayti, where it does 

 not exceed a width of 5 or 6 miles ; thence westerly, 

 south of Navassa Island, with a tongue to the northward 

 between Navassa and Foxmigas Bank, and another to 

 the westward between Foxmigas Bank and Jamaica. 



A line of soundings was run from San lago de Cuba 

 to the east end of J.amaica, where a depth of 3,000 

 fathoms was found 25 miles south of Cuba. This deep 

 place was found by subsequent soundings to be the 

 eastern end of an immense deep valley extending from 

 between Cuba and Jamaica, to the westward, south of 

 the Cayman Islands, well up into the Bay of Honduras. 

 The Cayman and the Misteriosa Bank were found to be 

 summits of mountains belonging to a submarine extension 

 (exceedingly steep on its southern slope) of the range 

 running along the south-eastern side of Cuba. This deep 

 valley is quite narrow at its eastern end, but widens 

 between the western end of Jamaica and Cape Cruz, 

 where the soundings were 3,000 fathoms within 15 miles 

 of Cuba, and 2,800 fathoms within 25 miles of Jamaica. 

 Near Grand Cayman the valley narrows again, but within 

 20 miles of this island a depth was found of 3,428 fathoms. 

 The deep water was carried as far as a line between 

 Misteriosa Bank and Swan Islands, with 3,010 fathoms 

 within 15 miles of the latter. On a fine between 

 Misteriosa Bank and Bonacca Island there was a general 

 depth of 2,700 fathoms, and a depth of over 2,000 fathoms 

 extended well into the Gulf of Honduras. Between 

 Misteriosa Bank and Chinchorro Bank the soundings 

 were regular at 2,500 fathoms. North of Misteriosa and 

 Grand Cayman, to the Isle of Pines and Cape San 

 Antonio, the soundings were generally 2,500 fathoms. 

 The serial temperatures agree', in relation to depth, with 

 those obtained in the Gulf of Mexico, by Lieut. Commander 

 Sigsbee, and in the Eastern Caribbean by Commander 

 Bartlett ; decreasing from the surface to 39^° at 7C0 

 fathoms, or Icis, and constant at that temperature for all 

 depths below 700 fathoms. At greater depths than 600 

 or 700 fathoms the bottom was always found to be 

 calcareous ooze composed of Pteropod shells with small 



