NATURAL PHILOSOPHY. 191 



eating with the outer air, and so keeping up a blast of cold air through the 

 pipes, thus preventing their expansion by heat. 



Mr. Walker remarked, that the cold air must be blown upon the exterior 

 of the pipes as well as upon the interior. Moreover, the front pipes of an 

 organ were generally more affected by the heat than the interior pipes. 



The Chairman said, that, with regard to Mr. Hullah's remarks, he would 

 say that every mathematician, at first sight, might have a strong bias in 

 favor of what Mr. Hullah called his standard of 512. Chladnir had founded 

 his system upon that number, and no mathematician who expressed the 

 relation of musical notes in numbers, could fail to be struck with the advan- 

 tage for such purposes of that scale, which gave tg the middle C 512 vibra- 

 tions per second. That did not give A a whole number, but it gave a great 

 amount of whole numbers, and in many ways was convenient. On the 

 other hand, the numerical advantages of the standard were not important. 

 Where the note was determined, they knew that it was by the number of 

 vibrations, whether counted in fractions or decimals, and by that means 

 they could recover the note at any time. Therefore, he thought the con- 

 veniences and inconveniences were of another kind, and must be considered 

 by practical musicians. The difficulty urged by one speaker, that a change 

 of pitch would involve the destruction of a great body of existing instru- 

 ments, was one which must not be overlooked, though some of them, no 

 doubt, might be modified. The alterations of organs to the new pitch would 

 also be a matter of considerable expense. These were difficulties of far 

 more importance than any want of symmetry in numerical calculations. 

 Still, if the French system were adopted over a great part of Europe, so far 

 as there were any perceptible difference between that and 512, musicians 

 would gain more by adopting it than mathematicians would lose. 



A committee, of which Dr. Arnott is Chairman, was then appointed to 

 consider the whole subject, and report at a future meeting. 



INTERESTING BALLOON VOYAGE. 



The greatest balloon vovagc on record, was performed on the 1st and 2d 

 of July, by Messrs. Wise, LaMountain, Gager, and Hyde, four persons, 

 who passed over a distance of eleven hundred and fifty miles in nineteen 

 hours, or from St. Louis, in Missouri, to Henderson, Jefferson County, Xew 

 York. The special object of the experiment was to establish the existence 

 of a constant current of air, at a high elevation, from west to east, over the 

 Xorth American continent, and, by means of it, to pass in the balloon from 

 St. Louis, on the Mississippi, to a point on the Atlantic sea-board. The 

 ascension was made from St. Louis, at 7.20 P. M., on the 1st of July, and 

 the course at starting was north of east. During the night nothing of any 

 particular moment occurred, the balloon sailing along in a north-east- 

 erly direction, at a varying height above the earth from five hundred to 

 ten thousand feet. The sky was clear, and the whole dome of the heavens 

 is described by Mr. Wise as " lit up with a mellow phosphorescent light. So 

 remarkable was this phosphorescent light of the atmosphere, that the bal- 

 loon looked translucent, and looked like light shining through oiled paper. 

 We could also tell prairie from forest, and by keeping the eye for a moment 

 downward, we could see the roads, fences, fiekl^, and even houses, quite dis- 

 tinctly, at any elevation not over a mile, and even at the greatest elevation 

 we could discern prairie from woodland, and from water. Whenever v/e 



