200 



KNOWLEDGE ♦ 



the conditions to hold which we recognise in our own 

 atmosphere. This would happen in five miles out of 

 10,000 miles of depth, known to be occupied by gaseous 

 matter. 



Even taking into account the tremendous heat prevailing 

 in the sun, and the existence of much lighter gases in his 

 surroundings than exist in our own air, we cannot escape 

 conclusions scarcely less preposterous and assuredly quite 

 as inadmissible as we have thus reached. If the pressure 

 and density did not double in less than a mile, or than 

 ten miles, or even a hundred, — which is altogether impos- 

 sible—wo should still have, within a range of 10,000 miles, 

 10,000, or a 1,000, or a 100 doublings (in these cases 

 respectively) ; and consequently even with the least of 

 these numbers there would be a density at the base of 

 the 10,000 miles exceeding a billion billicn times * the 

 density of our own air. 



Undoubtedly it is not in the high temperature of gases 

 near the sun, or not in this only, that the solution of the 

 enigma lies. We have also to take into accoamt the 

 freedom of movement which exists throughout the 

 gaseous envelopes of the sun, and the constant move- 

 ments which are no doubt taking place within these 



In some sucli way, I think, we must encounter the 

 difficulty, kindred in character if not so great in degree, 

 which exists in Jupiter's case. We must admit the 

 existence of intense heat throughout the gaseous sur- 

 roundings of Jupiter, though we need not imagine that 

 they are as hot as the gaseous envelopes of the sun, or 

 that their temperature ever approaches solar tempera- 

 tures. We must admit great freedom of motion within 

 these gaseous and vaporous regions around Jupiter. So 

 may we at once escape the difficulty which Jupiter 

 assuredly presents, and be led to the conclusion which 

 we had already reached from another side, — viz., that 

 Jupiter's outer portions to a depth of many hundreds of 

 miles within his visible surface do not belong to his real 

 globe, but are mainly formed of gaseous, vaporous, and 

 cloud-like matter. 



From yet other directions the same result has been 

 reached, as I pointed out in my "Other Worlds than 

 Ours," many years before the great spot had appeared. 

 No one now supposes that Jupiter is made of other 

 materials than those which form the earth on which we 

 live, nor does any one now suppose that Jupiter is a 

 hollow planet as Sir David Brewster insisted. Tet if we 

 do not adopt one view or the other we cannot possibly 

 explain the small mean density of Jupiter otherwise than 

 by assuming that the globe we measure for Jupiter is 

 very much larger than the planet itself. Jupiter is 

 1,250 times as large as the earth, but only 310 times as 

 massive. This, alone, proves that the real globe of 

 Jupiter lies far within the cloud-strewn surface we 

 measure. With the enormous attraction residing in 310 

 times the earth's mass, a globe of the same materials as 

 our earth would be considerably denser instead of less 

 dense than the earth. Assigning to Jupiter a density 

 only equal to the earth's its diameter would be little 

 more than 50,000 miles. Jujnter's diameter is fully 

 80,000 miles. The distance of the cloiid-strewn surface 



* In the first twenty donblings equality with our atmospheric 

 pressure would bo attained, in the next twenty the pressure would 

 be a million times greater, in the next a billion times, in the fourth 

 twenty doublings the pressure would be a trillion times, and in 

 the last twenty it would be raised to a quadrillion times the 

 pressure at our sea-level. (I use the English system of numeration 

 according: to which a million raised to the second power is a billion, 

 to the third power a trillion, to the fourth a quadrillion, and so 



it \\^ .^' I -^ . Ill 



ju-st-uamul ill . 



The teles.-i. 



better with ili 



he has an atrm 



I' nf tlir jilanet, cannot then, 

 I'l, 111)1) niilfs (the difference 

 .i)M(i ni,!,.s, the halves of the 



I Jupiter corresponds much 

 Milt than with the idea that 

 • least resembling our earth's. 



BAUDRE'S SILBX PIANO. 



AMONG the flint stones that are met with in the 

 chalk formation there are some that when struck 

 with another flint emit sounds of great purity. The 

 tones that are thus obtained with different musical flints 

 are out of all proportion to the bulk and weight of the 

 stone. This is a very curious phenomenon, the explana- 

 tion of which is not furnished by the fundamental laws 

 of acoustics, and which surely merits being studied by 

 physicists. 



As long ago as 1873, I spoke of musical stones as a 

 curiosity worthy of attracting attention. I then pro- 

 mised to return to this interesting subject, but the years 

 passed by, and the singing stones were forgotten. Upon 

 recently visiting the new electric lighting of the Grivin 

 Museum, however, they were casually brought to mind 

 again. After examining this interesting installation, I 

 was walking through the great hall of the museum, 

 looking at the wax figures mounted therein, when I 

 heard some deliq-htful music that attracted my attention. 

 Approaching tlu' s]int ^\lu■r(_■ these harmonious and pure 

 sounds were luiii;_;' piMiluri'il, I saw a musician, who, 

 holding two Hints, was jilaying upon a stone piano with 

 wonderful agility, by striking other flints of all shapes 

 suspended by two wires at a few fractions of an inch 

 above a sounding-board. I at once made the acquaintance 

 of the player, who was Mr. H. Baudrc, a distinguished 

 musician and a zealous collector of musical stones. 



" How did you procure these flints that render so 

 delightful sounds, and from which you get so remarkable 

 music?" said I. 



" Ah, sir, it required much time and many trips to 

 collect the twenty-six stones which you see before you, 

 and which form the two chromatic octaves. It took me 

 more than thirty years (from 1852 to 1883), to search for 

 them in the chalk- beds of Haute-Marne, Perigord, Eure, 

 and the Paris basin." 



"Are such flints found in all chalk formations ?" " I 

 believe not ; the inuunu r.iMr i|u:nitities of English flint 

 have yielded me uothiiiLi- ainj taMc" "Are there any 

 works that treat of tins luti rcstiiiLC subject of singing 

 stones?" "I do not know; but I have letters from 

 numerous scientists, who have been pleased to con- 

 gratulate me, or to give me their opinion." 



" Would you communicate a few of them to me ? I 

 should like to publish them in La Nature." " Very 

 willingly, sir ; I will send you my file to-morrow." 



The following are a few of the notes that appear to 

 me to give some new information in regard to singing 

 stones. 



M. Cartailhac, director of the Toulouse Museum, re- 

 ports that three musical flints were once noticed by a 

 missionary in the villao'e of Chaffa, in the centre of the 

 plain of Thuiiiazana, Aliv.-.inia. Tln.-r stonrs were 

 hung by tlnvails fr..>a a ' laaa/. aiia I v,..i.!.i, ivil, and 

 were used for callir,,' tl.r [..iilifii! <■■ j i„v.r> i r t.i liattle. 

 They were struck with auutbor Hint, and their sounds, 

 which were very intense, were heard from some distance. 



In an interesting letter to M. Baudre from Mr. J. 



