in both these cases; nay, I even fufpect, that the purple colour is generally occafioned by a less heat than any of the other colours. "Had I met with this curious experiment of M. Marggraaf's before I obferved the prifmatic colours at first, it is not improbable but that this undertaking of mine would have been fhortened confiderably, by falling upon a different train of experiments. However, lince the method I have taken hath been productive of fome material information, it may, upon the whole, perhaps, be as well as it is; for in these curious researches, where a series of experiments were my guide, many circumftances confpired to throw more light upon the fubject than I might probably have found by proceeding upon a different plan. "In confequence of my fteadily purfuing thofe experiments, step by ftep with great application and industry, and obferving every circumstance in each experiment with all the care and attention I was able, in hopes of tracing out fome fecret principle upon which the phofphoric power depended, chance threw into my way fo uncommon an object, that I confidered it as a treasure in experimental philofophy to exercife my moderate talents upon. No day paffed, from that time to the completion of thefe obfervations, without making fome new experiments, or enlarging my ideas; and, after having extended my refearches fo far as to be able, at all times, by the fimpleft means, to produce the prifmatic colours fo very intenfe and beautiful, without ever failing in my attempts; it now appears a matter of very great furprife, how I avoided ftumbling upon the difcovery immediately after I had obferved the effects upon the thells that were calcined in the cracked crucibles mentioned before in an early part of this work. What a deal of fatigue and trouble would the putting of an oyster-fhell into the fire have prevented! who would have thought that fo fimple an operation could have produced fuch extraordinary appearances? and that thofe appearances, fimple as the operation is, fhould have efcaped the obfervations of philofophers, and thofe particularly who have interested themselves in these matters for fo many years paft? But experience teaches us daily, that, dur ing an over eagerness in our purfuits to attain fome favourite point, we generally overlook others of a more extraordinary nature. Perfe verance, in the end, however, fometimes makes great amends for thofe overfights, by difclofing gradually the object we are in fearch after; but it must be acknowledged, that chance is frequently more generous, by removing the veil at once, when we the least think of it. For my part, I have been greatly obliged to chance upon this and many other occafions; and, had it not been frequently taken notice of before, I should have enumerated fome of the greatest difcoveries that have been made by others entirely through accident. "In this work we have fhewn, by a great variety of experiments, how the prifmatic colours may be exhibited in the dark as phofphori. Why may not chance hereafter, by fome lucky combination of circumftances, again produce fome difcovery, in confequence of thofe extraordinary appearances, that may turn out to be of far greater importance? Attention and industry feldom fail of producing fomething worthy the notice of philofophers." P 2 Τα At To this laft reflection we readily fubfcribe; admitting that the world is greatly obliged by the induftry of fuch philofophers, who give themselves fo much trouble and beftow fo large a portion of their time, to investigate the phenomena of nature. the fame time, however, we cannot help remarking how much more fuccefsful they are at experiment than at conjecture: for fuch we must call moft of the theoretical conclufions they deduce from their practical obfervations: it would be ungrateful and invidious to particularize any fuch in the publications of fo profeffed and ingenuous an experimentalift, as the Author of the work before us. ART. IV. Philofophical Tranfactions. Vol. LXV. For the Year 1775. Part I. Continued fram page 115, and concluded. The next, and only, articles we fhall farther particularly notice, are the Vth and VIth, containing the account of a curious mufical inftrument brought from the South Seas; with remarks on the fame, and obfervations on the nofe flute of Otaheite. "Art. V. Account of a Mufical Inftrument, which was brought by Captain Fourneaux from the Ille of Amfterdam, in the South Seas to London, in the year 1774, and given to the Royal Society. By Joshua Steele, Efq. in a Letter to Sir John Pringle, Bart. P.R.S. то SIR JOHN PRINGLE, BART. P.R.S. SIR, Margaret-fireet, Cavendish-square, Agreeable to your request, I have examined the curious fyftem of pipes, brought by Captain Fourneaux from the South Seas. The refult of my experiments are herewith inclofed. The inftrument was fo new to me, that I fhould be forry its reputation should rest intirely on my report, as I think an expert blower of the German flute might make further difcoveries; towards which, my obfervations, whether perfectly accurate or not, may in fome measure ferve as a guide. The accident of a flat third, coming in the ftead of a fharp one, from the pipes 6. 7. 8. and 9. is fo extraordinary, that I fufpected, for fome time, the lowest (or fundamental) tones of those pipes were a quarter tone (or diefis) lower than I have marked them; but, after repeated trials, and by the best judgement I could form by my ear, and by comparison with another inftrument, I gave up that fufpicion; and being confirmed in the opinion, that the moft acute tones I could obtain from thofe four pipes, were minor thirds to the moft grave, I have ventured to mark them fo. The reason why there was room for my doubt above mentioned is, because the difference of hotter or colder, moifter or dryer, has a fenfible effect on the acutenefs or gravity of the tones. I am, Sir, with great regard, your most humble fervant, JOSHUA STEELE." Figure "Explanation of the fyftem of mufical pipes brought from the Ile of Amfterdam in the South Sea, by Captain Fourneaux, to London, anno 1774, from experiments made by Mr. Steele. "The manner of blowing thefe pipes, in making these experiments, was the fame as people ufe to whistle in the pipe hole of a drawer key. Of the tones, marked on the drawing, the upper feries, which are exact fifths to the lower, are eafieft produced by an unexperienced perfon; and the lower feries, which we will call fundamentals, with fomewhat more addrefs and a weaker blaft. Befide the above mentioned tones, if the velocity of the breath be increased a little, the five first pipes will give octaves to the fundamentals; and if farther increased, fharp thirds, or tierces, above these octaves. In the pipes 6. 7. 8. and 9. I could neither make the octaves to the fundamentals, nor the fharp tierces; but in their stead, the minor, or flat-third, above the octave came, when the breath was urged beyond the degree requifite to produce the fifth. This minor third is an accident out of the natural order of tones produced from fimple tubes, which I do not pretend to account for. Here following, are fet down the notes of the feveral tones which I produced from each pipe; but, in order to bring them more within compass of the scale of five lies, they are written an octave lower than they really are on the pipes. And also those tones which come with most ease are wrote in minims, as thofe in the next degree, in crotchets, as thofe ftill more difficult, in quavers, as and the most difficult in femiquavers, as Por d or or E ΟΙ These tones are adapted to English confort pitch, by the above notes. From whence it is evident, that an expert performer may exhibit the following feries, and perhaps alfo the octave to the fundamental ; videlicet,& , though I could not, which feries is fuf ficient for an infinite number of airs: In this feries the notes marked in minims, being those which are easiest to be founded, furnish two fyftems which correspond with the definitions of the diatonic and chromatic genera, according to Euclid, who defcribes the diatonic in defcending, καλὰ τόνον, καὶ τόνον, καὶ ἡμιλόνιον ; and in afcending, καθ ̓ ἡμιονιον, καὶ τόνον καὶ τόνον. as defcending, and afcending. And the chromatic thus, κατὰ τριημιτόνιον, καὶ ἡμιόνιον, καὶ ἡμιλόνιον, in defcending; and afcending, καθ' ἡμπόνιον, καὶ ἡμπόνιον, και τριημιτόνιον. as defcending, and afcending. "But as the enharmonic genus requires intervals of the diefis, or quarter tone, and as it did not appear by these experiments, that the pipes could exhibit any founds by fuch intervals, I conclude they are not capable of performing according to the enharmonic divifion of the tetrachord. "VI. Remarks on a larger Syftem of Reed Pipes from the Isle of Amfterdam, with fome Obfervations on the Nofe Flute of Otaheite. By Jofbua Steel, Efquire. то SIR JOHN PRINGLE, BART. P.R.S. SIR, Margaret-freet, Feb. 21, 1775.. "The notice taken of my fmall endeavours, by your illuftrious fociety, does me much more honour than I deserve; however, I receive it, as I ought, with respect and gratitude. I now inclofe to you fuch farther remarks as I have been able to make, by repeated trials, on the last reed pipes you brought me from Mr. Banks; which, though much larger, and more in number, are of the fame genus with the former. I have alfo examined the nofe-flute of Otaheite, which Mr. Banks favoured me with; and I find it gives only four founds, with the first degree of breath, which are, in an ascending feries, by a femitone, a tone, and a femitone. Thus noted in confort pitch, |