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Paçe 65. Some good regulations are proposed in the maste ner of figuring basses for accompaniment; but it is unfortunate for thorough-bass players, that after fuch pains have lately heen taken to fimplity the rules and regulate the figures regre. sentative of chords, no basses in printed music are now figured; but in fongs, to preclude the neceflity of learning the rules of practical harmony, an accompaniment for the piano. forte, harp, and guitar, is given in notation instead of figures.

The author, in hasty writing, employs more clian once the expression of refling bass; would it not be Leiter, and less equivocal, when the rolling-press is again set to work, to say a fustained, holding, or continued bass? A refiing bass may be mistaken for a bass at refi.

Mr. Shield, by writing appoggiaturas in large notes, renders it necessary to higure them; which is a new practice. P. 68, line 1, the appoggiatura in the third fragment which precedes the d, is of equal importance with those in large notes; yet Mr. Shield has not figured it. · The three pages, 70, 71, and 72, are very well occupied by expedients for avoiding a succesion of sths. Perhaps p. 73 might have been better employed than by burlesquing recitative; but as the author, farther on, makes the amende honorable to this important species of dramatic music, we shall quit his piece of humour with a smile instead of a frown).

Thie beautiful fragments given pp. 77 and 79 fhould not appear as foundlings, and fatherlels. Here we have again to object to the provoking system of concealing nanies.

Part III. P. 8510 88. On recitative. Upon this subject, the author has candidly and judiciously quoted the late Mr. Brown, whose observations on dramatic mulic in Italy were profound, and his feeling exquisite. Mr. Shield laments the not being able to allow room for Mr. Brown's whole letter; and we unite in the lamentation from that portion of it which Nr. Shield has inserted, together with two pages of admirable Speciinens of recitative accoinpanied. Mr. Shield has likewise not only given excellent fpecimens of cantabile, but two of bravura, without any previous indication of them. But musicians, as well as painters, should know the hands of great müfters at the first glance.

The imitations which Mr. Shield to jusly adinircs, at the bottom of p. 91, for their ingenuity, have a defect in accent of which the soung student should be apprised: the greus author of the gioretto los certainly, from inadvertence or a capricious design, introduced a paslage into a triple-time movemeni, which manifeflly buicogs to common-time. The accents of the two histo bars coinc wrong, and on different parts of cach of these bars.

Upon examining with delight the trio of Conrade the good, we cannot help returning once more to the charge, and exclaiming to Mr. Shield, · Why, in the name of mystery, keep out of light the name of the author of that exquitite coinpolition?' There may be reasons for suppressing cenfure, but well-deserved praise may safely be bestowed.

The instructions given, p. 95, for writing for wind in fruments, will greatly enlighten a young composer. And the [wenty-seven modulations, chiefly extraneous, and difficult to bring about without offending the car, will be a curious and useful study for those who wish to explore unbeaten paths in the regions of harmony.

Betides scarce and curious compositions, Mr. Shicid lias furnished his work with many pleasing productions of a more familiar kind.

The elaborate accompaniments given at p. 100, to · Oi! ponder well,' in the Beggar's Opera, in the true serious opera style, are very ingenious; but this old tune, tricked up in so elegant a manner, is not the original air, which is in triple-time, and the new edition of it in common-time. It is doubtless a better melody, and better accompanied, than that printed in the first editions of the Beggar's Opera, 1729 ; but whether it would have been more approved by Gay, whose design was to burlesque the Italian cpera, we kuow not. The merit of Dr. Pepusch's simple basses to these national and vulgar tunes, is not only in science but propriety, as they neither disguise the melody, nor obscure the words. Played upon instruments, or sung to serious words, the lamentable village and street draw! would be loft, nor would the 'poor babes in the wood' ever be thought of.

Though, in general, we niuch respect the oracle alluded to by our author, p. 107, yet we cannot implicitly fubmit to its decree concerning modulation. I imagined (says Ni;. Shield) that it could not exist without a change of key. But an o:acle says, “ Modulation is the art of rightly ordering the melody of a single part, or the harmony of many parts; either keeping in one kev, or in pafling from one key to another.” “God lave great George our king,' is given on this extensive plan as an example of modulation, in which there is no real modulation according to the present acceptation of the word. If one great master were delired by another to fit down to a keyed-inftrument and modulate, his hearers would be much disappointed if hc contined his harmony to one key only. According to the oracle, modulation is melody, harmony, mufic-it is every thing, and nothing. But the import of the word in the present in utical technica, is as well understood as that of fiat, iharp, crotchet, or quaver. Books have been written on modulation, and rules for passing froin one key to another, relative or ex, traneous. The oracle's definition is such as a man of letters perhaps would give, who is wholly ignorant of music. But Mr. Shield was too humble and subinissive to authority in adopting such an unscientific definition in preference to his own conception, which was just, short, and intelligible to every tyro in thorough-bass or composition. The verb to modulate, may, in careless language, be extended to a change of chord, or even single note; but as a technical word among musicians, it is, we believe, generally understood, as Mr. Shield imagined, a change of key. Every accidental flat or sharp in a musical composition, if accompanied by a baís, is modulation. The word is perhaps nearly fynonimous with transition.

Pages 116 and 117 contain an inedited studied cadence, per. formed at Bach and Abel's concert, to an admired concertante, and to an admiring audience. We must not say by whom this ingenious cadence was composed left it should divulge a secret which the author of the work before us so sedulously tries to preserve.

At p. 118 we have a pretty imitation of a Russian air, adapied to the piano-forte. And at 119, the famous Swiss air, the Rans des Vaches. . 120. The rough score of the soldier tired of war's alarms,' with the author's corrections and cancels. 121. Vocal divisions from vo folcando and other bravura airs for the exercise of the voice.

122. Numerous examples of equivocal modulation, or modern enharmonic, extremely useful in these our days of licen. tious changes of keys. Exercises of the same kind for the violoncello or tenor.

124. An exercise containing abrupt modulations for the violin, with a modulation which has a peculiar enharmonic change in it for the violin or tenor, with instçuctions for the shifts and fingering.

Upon the whole, though this introduction may not be deemed a regular treatise of either practical or theoretical music, nor found to include all the elements of music in general, or the practice of any particular instruinent complete ; yet we may say with truth, that it contains more miscellaneous and useful 'knowledge of composition, and the practice of almost every species of instrument most in use, than any other book of instruction which has come to our hands.

Esays, Political, Economical, and Philosophical. By Benjamin

Count of Rumford, Knight of the Orders of the White Eagle, &c. Vol. II. 8vo. 8s. Boards. Cadell and Davies.

THE second volume of these Essays is not less interesting than the former *: in a philosophical view it is more so, since it contains some valuable additions to the former stock of science, applicable to the moft useful purposes.

The sixth essay, the first of the present volume, is on the management of fire and the economy of fuel. It is needless to enlarge on the utility of the inquiry, fince, in many places, fuel is with great difficulty procured, while some philosophers have supposed, that even the mineral strata which afford it may at no great distance from the present period be exhausted, In another view the object is important. When no more heat than what may be necessary for the operation is procured, and the whole is consumed, not only the large proportion so injurious to the domestics employed, and to the health of the inhabitants of large cities, is prevented from adding to the heat of the air, but the vapours which increase the injury are destroyed. If also the smoke could be blended with the steam, in the second operation of heating the water in the upper boilers, much of its deleteriousnature might be destroyed, with out any diminution of its heat, as the water, deposited on cooling the steam, would absorb the carbonic acid air in the vapour.

Great are the advantages arising from our author's æconoinical contrivances. They reduce the quantity of fuel to 1, and sometimes even to it of what is ordinarily consumed; and this is effected not only by preventing the escape of the smoke and compelling it to communicate its heat before it escapes, but by interpoling non-conductors of heat between the boilers, as well as the various canals through which the heated smoke or steam passes, and the open air. The best and most convenient non-conductors is common air; but this is a subject with which our readers are sufficiently acquainted, from two papers by count Rumford, published in the Philosophical Transactions, noticed in our LXIIId volume, p. 321, and in our VIIth, N. A. p. 69, respectively.

In the third chapter, the couni gives a summary of the doctrine of conductors of heat, and adduces an experiment to show that steam is not one of these.

"That steam is not a conductor of heat, I proved by the following experiment: A large globular bottle being provided, of very thin and very tranfparent glass, with a narrow neck, and its bottom drawn inward so as to form a hollow hemisphere about fix inches in diameter; this bottle, which was about eight inches in diameter exter

* See our XXVIIIth Vol. New Arr. p. 319.

nally, being filled with cold water, was placed in a shallow dill, or rather plate, about ten inches in diameter, with a flat bottom formed of very thin Cheet brass, aud raised upon a tripod, and which contaived a small quantity (about io of an inch in depth) of water; a spirit lamp being then placed under the middle of this plate, in a very few minutes the water in the plate begin to boil, and the hollow formed by the bottom of the bottle was filled with clouds of steam, which, after circulating in it with surprising rapidity four or five minutes, and after forcing out a good deal of air from under ihe boi*tle, began gradually to clear up. At the end of eight or ten minutes

(when, as I supposed, the air remaining with the steam in the hollow cavity formed by the bottom of the bottle, had acquired nearly the same temperature as that of the stean:) these clouds totally disappeared; and, though the water continued to boil with the utmost violence, the contents of this hollow cavity became so perfeétly invisible, and so little appearance was there of fieam, that, had it not been for the streams of water which were continually running down its sides, I Diould almost have been templed to doubt whether any fteam was actually generated.

• Upon lifting up for an instant one side of the bottle, and letting in a smaller quantity of cold air, the clouds instantly returned, and continued circulating several minutes with great rapidity, and then gradually disappeared as before. This experiment was repeated feveral times, and always with the same result; the steam always becoming visible when cold air was mixed with it, and afterwards recovering its transparency when, part of this air being expelled, that which remained acquired the temperature of the fieam.

Finding that cold air introduced under the bottle caused the steam to be partially condensed, and clouds to be formed, I was defirous of seeing what visible effects would be produced by introducing a cold folid body under the bottle. I imagined that if steam was a conductor of heat, some part of the heat in the steam paffing out of it into the cold body, clouds would of course be formed; but I thought if steam was a non-conductor of heat,--that is to say, if one particle of steam could not communicate any part of its heat to its neighbouring particles, in that case, as the cold body could only affect the particles of steam actually in contaêt with it, no cloud would appear; and the result of the experiment Mowed that steam is in fact a non-conductor of heat; for, natwithstanding the cold body used in this experiment was very large and very cold, being a solid lump of ice nearly as large as an hen's egg, placed in the middle of the holow cavity under the bottle, upon a sinall tripod or frand made of iron wire; yet as soon as the clouds which were formed in confequence of the unavoidable introduction of cold air in lifung up the bottle to introduce the ice, were disipated, which [mon happened, the steam became so perfectly transparent and invili ole, that not the finallest appearance of crudineí: was to be seen any where, not even about the ice, which, as it went on to melt,

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