Nov. 16, 1883.] 



♦ KNOWLEDGE ♦ 



309 



aud as the organ by which it is elaborated is under the influence of 

 the nervous sj-stem, these insects have the power of increasing or 

 diminishing their light." E. 0. E. 



[1005] — Your correspondent, Jlr. Vos, in this week's Knowledgk 

 has pictured just such an animal as was brought a few months ago 

 by the grocer's boy in a box containing eggs, which were packed in 

 straw. Its glowing appearance in the straw attracted attention, 

 jind it was thought to be a glowworm. On turning up the light, 

 however, and examining it with a magnifying glass, I found it to 

 be a kind of centipede. Putting out the light did not restore its 

 luminosity ; it appeared to have the power of emitting or with- 

 holding its light at pleasure. 



Your answer to " Harry " reminds me that the self-same question 

 was set at an examination of pupil-teachers a few months since, 

 and, I believe, floored the greater part if not all of them. As you 

 say, seven is not near the answer. One is apt at the first glance to 

 overlook the fact that trains are already on the same line of rails 

 as the train in which the " counter " starts besides those running on 

 the return line, so that both sets will have to be met. W. \V. S. 



[1000]— It is a well-known fact that one or two British centipedes 

 are luminous. The Kev. Leonard Jenyns, says in his " Observations 

 in Natmal History," p. 296 : — 



" Dec. 10, 1843. — A man brought me to-day what he called two 

 glowworms, which he had seen shining on a bank the preceding 

 evening. They proved to be only the electric centipede (Scolopendra 

 electrica), which is frequent in the autumnal months in this neigh- 

 bourhood (Swaffham Bulbeck, Cambridgeshire), and may often be 

 seen shining by roadsides, more especially on mild damp evenings. 

 They are constantly mistaken for glowworms by the common 

 people. These two individuals I kept alive in a small box with 

 damp earth at the bottom for several months ; but I never observed 

 them to shine once after they were taken. 



" The luminosity of this insect is remorkable for diffusing itself 

 over the ground, or the fingers of those who attempt to handle the 

 individual from which it emanates, in like manner as when pure 

 phosphorus is handled. I am not aware that this is ever the case 

 with the real glow-worm." And he adds the following note : I was 

 not then aware of the observations of Mr. Gosse, who states that he 

 found the light might be immediately reproduced by breathing upon 

 the centipede ; the experiment fails (it is said) if repeated too often 

 at once, though after the lapse of a day and night it will produce 

 the same results as at first." Cyphel. 



[1007] — There is a luminous'centipede, not at all uncommon ; I 

 have seen it several times. 



About ton days ago, when walking in my garden in the evening, 

 I observed something shining, and supposed it to be a centipede ; 

 but on examining it with a light, I found it to be a part of the dead 

 body of a snail ; and the night before last, on noticing a similar 

 light, I discovered it to be a part of the body of a dead worm. I 

 should think it was something of the latter kind that Mr. Fenton 

 saw. The light in these cases would doubtless be caused by 

 chemical change. J. Dyer. 



DISCOVERY OF AMERICA. 



East Berar. 

 [1008] — Quatrefages, in his book " The Human Species," Chap. 

 XVIII., on Migrations in America, writes: — "In 986, Bjarn 

 Meriulfson, when on his way to Greenland, was carried by a storm 

 as tar as New England. In 1000, Leif, the son of Erick the Red, 

 started for the country discovered by Bjarn. Accompanied by 

 thirty-five men, he ran down as far as Rhode Island, where he found 

 the vine, and gave the name of Vin-land to the country, which ho 

 took ])Ossession ; he built Leifsbudir, passed the winter there, and 

 noticed that the shortest day began at half-past seven and ended at 

 half-past four. This observation, which agrees with all the other 

 details, places Leifsbudir near the present town of Providence, 



41° 21' 10", N. lat The colonies founded in Greenland by 



Erick .... multiplied rapidly ; both the cast and west coast 

 were peopled. Then two centres bore the name of Osterbygd and 

 Vesterbygd .... as early as 1121, an Irishman, Erick Upsi, was 

 created Bishop of Greenland, and had eighteen successors. Vinland 

 was in the jurisdiction of tliis diocese. The tithes of this country 

 figured among the revenues of the Church in the fourteenth 

 century, and were paid in kind. ... In 141S it still paid to the 

 Holy See as tithes and Peter's pence 3,600 lb. of walrus tusks. . . . 

 Shortly afterwards ileotsof pirates, springing from soiue unknown 

 ([uarter, came down upon and pillaged them ; the temperature of 

 both land and sea gradually fell ; voyages became more and more 

 'liflieult, and, at last, ceased altogether." 



In comparatively bookless India I have no resource but to ask 

 you, is all the above true ? Columbus discovered America in 1492, 

 as if previously unknown, yet only 74 years before Vin-land paid 

 tribute to the Pope, and all knowledge of the fact seems to hare 

 been forgotten. It would also be curious to find out the unknown 

 quarter the pii-ates came from. Is it authenticated ? As also is 

 the fall in temperature, which seems extraordinary ? If in 1418 

 there was a Bishop with Rhode Island in his diocese, can Columbus 

 be said to have discovered America at all ?. Edu. B. 



THREE TIMES GREATER THAN. 



[1009] — My attention was lately drawn to an opinion expressed 

 by a learned judge upon ithe meaning of a not uncommon phrase, 

 occurring in a certain Statute, namely, " three times greater than," 

 which phrase his lordship held to be synonymous with the expres- 

 sion " three times as great." 



Counsel argued that if (as was the opinion of the judge) 4| was 

 three times greater than 1^, then 3 would be two times greater 

 than IJ, and IJ would be one time greater (1) thanl|; but he 

 failed to convince the judge. The same argument, if inverted, 

 seems ever more forcible ; for instance, granted that " J (or, indeed, 

 any fraction) greater," would represent an increase of size over the 

 object compared with, then " one time greater" must mean double 

 the size, " two greater " treble the size and so on. 



The case referred to is to be found in No. 22, " Jtistice of the 

 Peace," p. 431. A. Eogeks Wood. 



[1010]- 



CONTRACTED MULTIPLICATION. 



71-380164 X 2-7354 

 2-7354 



214110492 = product by 300 

 1927261428 =3x9=27000 

 3854528856 = 2x27 = 54 



195-2533006056 



27-14986 + 92-41035 

 Reverse the multipliers. 

 27-14986 

 5301429 



24434871 



542997 



108599 



2715 



81 



14 



2508-9280 



[Viz., circ. 50 digits against 74 digits in a short sum.] First 

 shown to me by Prof. Steggal, of the New University College, 

 Dundee. Did Prof. Henrici mean this ? (From " Young's Arith- 

 metic") 



By the way, have you noticed how much one wants a comma, 

 aye, and a red one, in the second Collect at evening prayer : that 

 both, our hearts, &c., &c. ? F.\ciebat. 



DOUBLING OF POPULATION, CAPITAL, &c. 



70 

 [1011] — — is a simpler (though less close) approximation to the 

 r 



value of n than the formula .:: '■ given at p. 262 [972]. 



3r 

 The difference between the values given by the two formula! 

 cannot exceed J, and is when r is 2. G. 0. E. 



OBSCURE CAUSES OF DEATH BY DROWNING. 



[1012]— It has often happened to me (as to all swimmers, I 

 suppose) to swallow a mouthful of salt water, in spite of every care 

 not to do so. I have also often been near swallowing some small 

 object — a bit of cork or w-ood, a bloh of bladder-wrack, &c. Now, 

 it might happen that such a thing weilgod itself in the windpipe, 

 producing suffocation. The doctors finding that the cause of death, 

 would never think of cutting open the throat in search of the 

 caiiso, supposing the water sutiieient. But may not some such 

 accident account for the many cases where good swimmers have 

 perished without any cvhanstion to account for it ? It might be 

 prudent to wear a net tied over the mouth. Also lives might be 

 saved if men wl>en swimming far had a small flask of bi-andy round 



