Page 65. Some good regulations are propofed in the manner of figuring baffes for accompaniment; but it is unfortunate for thorough-bafs players, that after fuch pains have lately been taken to fimplify the rules and regulate the figures reprefentative of chords, no baffes in printed mutic are now figured; but in fongs, to preclude the neceffity of learning the rules of practical harmony, an accompaniment for the pianoforte, harp, and guitar, is given in notation inftead of figures.

The author, in hafty writing, employs more than once the expreffion of refting bafs; would it not be better, and lefs equivocal, when the rolling-prefs is again fet to work, to say a fuftained, holding, or continued bafs? A refling bass may be miftaken for a bafs at rel.

Mr. Shield, by writing appoggiaturas in large notes, renders it neceffary to figure 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 thofe 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 fucceffion of 5ths. Perhaps p. 73 might have been better employed than by burlefquing recitative; but as the author, farther on, makes the amende honorable to this important fpecies of dramatic mufic, we shall quit his piece of humour with a fmile inftead of a frown.

The beautiful fragments given pp. 77 and 79 fhould not ap pear as foundlings, and fatherlefs. Here we have again to object to the provoking fyftem of concealing names.

Part III. P. 85 to 88. On recitative. Upon this fubject, the author has candidly and judicioufly quoted the late Mr. Brown, whofe obfervations on dramatic mutic in Italy were profound, and his feeling exquifite. 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 Mr. Shield has inferted, together with two pages of admirable fpecimens of recitative accompanied. Mr. Shield has likewife not only given excellent fpecimens of cantabile, but two of bravura, without any previous indication of them. But muficians, as well as painters, fhould know the hands of great mafters at the first glance.

The imitations which Mr. Shield fo jufly admires, at the bottom of p. 91, for their ingenuity, have a defect in accent of which the young frudent fhould be apprifed: the great author of the quartetto has certainly, from inadvertence or a capricious defign, introduced a paffage into a triple-time movement, which manifeftly belongs to common-time. The accents of the two firft bars come wrong, and on different parts of each of thefe

bars.

6

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 fight the name of the author of that exquifite compolition? There may be reasons for fuppreffing cenfure, but well-deferved praise may fafely be bestowed.

The inftructions given, p. 95, for writing for wind inftruments, will greatly enlighten a young compofer. And the twenty-feven modulations, chiefly extraneous, and difficult to bring about without offending the ear, will be a curious and ufeful study for those who wish to explore unbeaten paths in the regions of harmony.

Betides fcarce and curious compofitions, Mr. Shield has furnifhed his work with many pleafing productions of a more familiar kind.

The elaborate accompaniments given at p. 100, to Oh! ponder well,' in the Beggar's Opera, in the true ferious opera fyle, are very ingenious; but this old tune, tricked up in fo elegant a manner, is not the original air, which is in triple-time, and the new edition of it in common-time. It is doubtlefs 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, whofe defign was to burlefque the Italian opera, we know not. The merit of Dr. Pepufch's fimple baffes to thefe national and vulgar tunes, is not only in fcience but propriety, as they neither difguise the melody, nor obfcure the words. Played upon inftruments, or fung to ferious words, the lamentable village and freet draw! would be loft, nor would the poor babes in the wood' ever be thought of.

Though, in general, we much refpect the oracle alluded to by our author, p. 107, yet we cannot implicitly fubmit to its decree concerning modulation. I imagined (fays M. Shield) that it could not exift without a change of key. But an oracle fays, "Modulation is the art of rightly ordering the melody of a fingle part, or the harmony of many parts; either keeping in one kev, or in paffing from one key to another." • God tave great George our king,' is given on this extenfive plan as an example of modulation, in which there is no real modulation according to the prefent acceptation of the word. If one great mafter were delired by another to fit down to a keyed-inftrument and modulate, his hearers would be much difappointed if he confined 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 prefent mufical technica, is as well underftood as that of flat, tharp, crotchet, or quaver. Books have been written on modulation,

and rules for paffing from one key to another, relative or ex, traneous. The oracle's definition is fuch as a man of letters perhaps would give, who is wholly ignorant of mufic. But Mr. Shield was too humble and fubmiffive to authority in adopting fuch an unfcientific definition in preference to his own conception, which was juft, fhort, and intelligible to every tyro in thorough-bafs or compofition. The verb to modulate, may, in careless language, be extended to a change of chord, or even fingle note; but as a technical word among muficians, it is, we believe, generally understood, as Mr. Shield imagined, a change of key. Every accidental flat or sharp in a mufical compofition, if accompanied by a bafs, is modulation. The word is perhaps nearly fynonimous with transition.

Pages 116 and 117 contain an inedited studied cadence, performed at Bach and Abel's concert, to an admired concertante, and to an admiring audience. We must not fay by whom this ingenious cadence was compofed left it should divulge a fecret which the author of the work before us fo fedulously tries to preserve.

At p. 118 we have a pretty imitation of a Ruffian air, adapted to the piano-forte. And at 119, the famous Swifs air, the Rans des Vaches.

120. The rough score of the foldier tired of war's alarms,' with the author's corrections and cancels. 121. Vocal divifions 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 licentious changes of keys. Exercises of the fame 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 inftructions for the fhifts and fingering.

Upon the whole, though this introduction may not be deemed a regular treatife of either practical or theoretical mufic, nor found to include all the elements of mufic in general, or the practice of any particular inftrument complete; yet we may fay with truth, that it contains more mifcellaneous and useful knowledge of compofition, and the practice of almost every fpecies of inftrument most in ufe, than any other book of inftruction which has come to our hands.

Effays, Political, Economical, and Philofophical. By Benjamin Count of Rumford, Knight of the Orders of the White Eagle, &c. Vol. II. 8vo. 8s. Boards. Cadell and Davies.

THE fecond volume of thefe Effays is not lefs interefting than the former *: in a philosophical view it is more fo, fince it contains fome valuable additions to the former stock of fcience, applicable to the moft useful purposes.

The fixth effay, the firft of the prefent 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 fome philofophers have fuppofed, that even the mineral ftrata which afford it may at no great distance from the prefent period be exhaufted. In another view the object is important. When no more heat than what may be neceffary for the operation is procured, and the whole is confumed, not only the large proportion fo injurious to the domeftics 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 defroved. If alfo the fmoke could be blended with the team, in the fecond operation of heating the water in the upper boilers, much of its deleteriousnature might be deftroyed, without any diminution of its heat, as the water, depofited on cooling the fteam, would abforb the carbonic acid air in the vapour.

Great are the advantages arifing from our author's œconomical contrivances. They reduce the quantity of fuel to, and fometimes even to of what is ordinarily confumed; and this is effected not only by preventing the efcape of the fmoke and compelling it to communicate its heat before it efcapes, but by interpofing non-conductors of heat between the boilers, as well as the various canals through which the heated smoke or fteam paffes, and the open air. The beft and moft convenient non-conductors is common air; but this is a fubject with which our readers are fufficiently acquainted, from two papers by count Rumford, publifhed in the Philofophical Tranfactions, noticed in our LXIIId volume, p. 321, and in our VIIth, N. A. p. 69, respectively.

In the third chapter, the count gives a fummary of the doctrine of conductors of heat, and adduces an experiment to fhow that fteam is not one of thefe.

'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 glafs, with a narrow neck, and its bottom drawn inward fo as to form a hollow hemifphere 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 fhallow dif, of rather plate, about ten inches in diameter, with a flat bottom formed of very thin fheet brafs, and raifed upon a tripod, and which contained a fmall quantity (about of an inch in depth) of water; a fpirit lamp being then placed under the middle of this plate, in a very few minutes the water in the plate began to boil, and the hollow formed by the bottom of the bottle was filled with clouds of steam, which, after circulating in it with furprising rapidity four or five minutes, and after forcing out a good deal of air from under the bottle, began gradually to clear up. At the end of eight or ten minutes (when, as I fuppofed, the air remaining with the fteam in the hollow cavity formed by the bottom of the bottle, had acquired nearly the fame temperature as that of the fteam) thefe clouds totally disappeared; and, though the water continued to boil with the utmost violence, the contents of this hollow cavity became fo perfectly invisible, and fo little appearance was there of steam, that, had it not been for the ftreams of water which were continually running down its fides, I should almost have been tempted to doubt whether any steam was actually generated.

Upon lifting up for an inftant one fide of the bottle, and letting in a fmaller quantity of cold air, the clouds inftantly returned, and continued circulating feveral minutes with great rapidity, and then gradually difappeared as before, This experiment was repeated feveral times, and always with the fame refult; the fteam always becoming visible when cold air was mixed with it, and afterwards recovering its tranfparency when, part of this air being expelled, that which remained acquired the temperature of the fteam.

เ

Finding that cold air introduced under the bottle caufed the fteam 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, fome part of the heat in the fteam paffing out of it into the cold body, clouds would of course be formed; but I thought if fteam was a non-conductor of heat,--that is to fay, if one particle of steam could not communicate any part of its heat to its neighbouring particles, in that cafe, as the cold body could only affect the particles of fteam actually in contact with it, no cloud would appear; and the refult of the experiment fhowed that steam is in fact a non-conductor of heat; for, notwithstanding the cold body used in this experiment was very large and very cold, being a folid lump of ice nearly as large as an hen's egg, placed in the middle of the hollow cavity under the bottle, upon a finall tripod or ftand made of iron wire; yet as foon as the clouds which were formed in confequence of the unavoidable introduction of cold air in lifting up the bottle to introduce the ice, were diffipated, which foon happened, the fteam became fo perfectly tranfparent and invisible, that not the finalleft appearance of cloudiness was to be seen any where, not even about the ice, which, as it went on to melt