but I remember their public papers called the insect the cicada septemdecem. I am afraid it would be in vain to speculate from these imperfect notices, upon the mode of their reproduction, or the period they remain inactive, or the changes they may undergo. It appears to be certain that they become a maggot before winter sets in, but whether this maggot (or grub) descends into the earth, I know not. I was at Carlisle (Pennsylvania) in 1794, but not in 1796-but I passed through it in 1798 during the early part of my excursion before named. It is probable that some tract or other of the United States is every year visited by these swarms; but I cannot agree with the statement in your extract of the locusts creeping immediately out of their husks, and hanging by their fore-feet tike tallow candles; the contrary is much more probable, and their exuvia will continue sticking under the leaves some days after the insect has flown. The holes they make in rising may be about three quarters of an inch in diameter, and the former error in that particular may be an error of the press. If you think this worth inserting you are welcome to it-and I may probably hereafter recollect some interesting particulars relative to that country. BEN. HOLDICH. COFFEE SIMMERER. To the Editor of the Monthly Maga zine. THE use of coffee becoming every day more extensive in this country, I presume that any suggestion for the improvement of that pleasing and salubrious beverage cannot prove unacceptable to the public. Under that persuasion, I beg leave to communicate a method of coffee-making, which I have long practised, and which I find to answer my purpose better than any other-though I have tried several, and bestowed on the subject a share of attention, which your readers will hardly deem censurable when apprised, that coffee has, for the last three years, been my only beverage, except morning and evening tea. My process, sir, is that of simmering over the small, but steady, flame of a lamp, a process at once simple, easy, and (without watching or attendance) uniformly productive of an extract se grateful to the palate and the stomach, as to leave me neither the want nor the desire of any stronger liquor. But, to accomplish this, a vessel of peculiar construction is requisite. Mine is a straight-sided pot, as wide at top as at bottom, and inclosed in a case of similar shape, to which it is soldered airtight at the top. The case is above an inch wider than the pot, descends somewhat less than an inch below it, and is entirely open at the bottom; thus admitting and confining a body of hot air all round and underneath the pot. The lid is double, and the vessel is of course, furnished with a convenient handle and spout. In this simmerer the extract may be made either with hot water or with cold. If wanted for speedy use, hot water will be proper, but not actually boiling; and, the powdered coffee being added, nothing remains but to close the lid tight, to stop the spout with a cork, and place the vessel over the lamp, where it will soon begin to simmer, and may remain unattended and unnoticed until the coffee is wanted for immediate use; it may then be strained through a bag of stout close linen, which will transmit the liquid so perfectly clear as not to contain the smallest particle of the powder. The strainer is tied round the mouth of an open cylinder or tube, which is fitted into the mouth of the coffe-pot that is to receive the fluid, as a steamer is fitted into the mouth of a saucepan; and, if the coffee-pot have a cock near the bottom, the liquid may be drawn out as fast and as hot as it flows from the strainer. If the coffee be not intended for speedy use; as is the case with me, who have my simmerer placed over my nightlamp at bed-time, to produce the beverage which I am to drink the next day at dinner and supper; in such case cold water may be used with equal, or perhaps superior, advantage, though I have never found any perceptible difference in the result, whether the water employed was hot or cold. In either case, it soon begins to simmer, and continues simmering all night, without ever boiling over, and without any sensible diminution of quantity by evaporation. With respect to the lamp-although a fountain-lamp is undoubtedly prefera ble, any of the common small lamps, which are seen in every tin-shop, will answer the purpose, provided that it contain a sufficiency of oil to continue burning bright during the requisite length of time. The tube or burner of my lamp is little more than one-eighth of an inch in diameter; and this, at the distance of one inch and three quarters below the bottom of the pot, with the wick little more than one-eighth of an inch high, and with pure spermaceti oil, has invariably performed, as above described, without requiring any trimming, or other attention, and without producing any smoke; whereas, if the wick were too high, or the oil not good, the certain consequences would be, smoke, soot, and extinction. One material advantage attending this mode of coffee-making is, that a smaller quantity of the powdered berry is requisite to give the desired strength to the liquor. The common methods require that the powder be coarse, in which state it does not give out its virtue so completely as if it were ground finer, whereas in this process it may be used as fine as it can conveniently be made, and, the finer it is, the smaller will be the quantity required, or the richer the extract-as I have agreea bly experienced, since I have been enabled, by the new invention of Messrs. Deakin and Duncan, of Ludgatehill, to have my coffee at once reduced to the proper degree of fineness by a single operation, without the tedious labour of a second grinding with the mill tightened. JOHN CAREY. West-square Lambeth; April 2. ITALIAN OPERA. From the Literary Panorama. The following article is not only curious in itself, as marking the anxiety of government, without whose sanction nothing of the kind can be attempted, or matured, to revive the talent of Opera writing; but also as describing what modern times demand as the essentials of an opera likely to be successful in the present day. The English reader will smile at the determination that there shall be one comic character in a comic opera. The times of Sentimental comedy, or what the French denominated La Comedie larmoyante, are over; and the call among the public is, for strong characters strongly combined. Perhaps, there may be great propriety in concealing the names of the writers; and in preventing preference; this must, in some degree check the intrigue of the theatre, against which merit is no protection; as some writers know but too well. The stipulation that answers should be given within a month after the reception of a piece, would prove extremely acceptable to many an English applicant for managerical protection. Programma of the Direction of the Royal Imperial Theatre of La Scala, at Milan. Dated April 5, 1816. I. From the date of the publication of the present Programma to the end of December, 1819, it shall be free to every Italian poet to send to the Committee of Direction Dramas, or Operas serious or comic. II. The communications must be sent post paid, addressed Al Signor Cavaliere Angelo Petracchi; or Al Camerino del R. C. Teatro Alla Scala, in Milano. III. The authors must carefully conceal their names. The pieces must be accompanied by a sealed note, containing their names, their address, and those of a person who may answer for them; the choice of whom is left to themselves. IV. The pieces so sent shall be examined by two of the directors, and by a third person chosen from among the most distinguished poets of the city of Milan.-Those pieces which shall be excluded from performance shall be returned to the author, or to the person commissioned to act as his deputy. V. One month after sending their pieces, the authors may expect a definitive answer, as to the reception or rejection of their performances, and in the latter case, they may receive them again immediately, with the unsealed note of address. VI. The pieces which shall be approved, will be placed in the director's drawer, from among which will be selected all the new works composed for the theatre during the time that the directors are in office, to the end of the Carnival, 1820; during which time will be represented at least one serious opera and two comic operas, in each year; with the usual approbation. VII. The directors engage to represent the pieces without any alteration, whether by the Musical composers, or the actors. In case the writers living at a distance should think alteration necessary, they will nominate a proper person to that office; or they will authorise the directors. VIII. The essential qualities demanded in the pieces of both descriptions, are beside purity of style, 1. That they shall be in two acts. 2. That they shall be neither too long nor too short. 3. That according to the prevailing taste, they include a greater number of musical pieces of combination than of airs. 4. That they combine interest and novelty with the pomp of the spectacle. 5. That in a comic opera there be at least one buffoon, or comic personage. IX. For each serious opera that shall be brought out on the stage, the sum of a thousand Italian lire will be paid; and for every comic opera eight hundred lire. X. When the piece is printed, after the title will be added-crowned according to the Programma of April 5, 1816. The author shall be at liberty to add his name, or not, according to his own pleasure; and he shall receive a present of twelve copies. XI. In case any piece sent for approbation shall be represented on any other theatre, the directors shall no longer be bound by the stipulation in Article IX. XII. The writers shall be authorized to demand information concerning their pieces sent, and even to withdraw them. XIII. After the Carnival of 1820, the pieces which shall remain in charge of the directors shall be transferred to their successors in the direction, if they shall think proper to continue the conditions fixed by the present Programma, or in case of the contrary, they shall await the determination of their authors. Done at Milan, in the Committee of the Royal and Imperial Theatre Alla Scala, April 5, 1816. PLAN TO PREVENT VESSELS FROM In small decked vessels, such as sloops, there are seldom more than three or four men to navigate them; so that if they spring a leak the fatigue becomes so great at the pumps, that the men are soon exhausted. When a sloop or small vessel is building, and before planking the bottom and sides, let the outside of the timbers be rubbed over with a mixture of pitch, tar, cow-hair, and powdered charcoal, made hot, and which, when cold, is of the consistency of cobler's wax: after rubbing the timbers on the outside with this composition, plank the bottom and sides: when the planks are caulked, fill all the spaces up between the timbers with this mixture, and also over the inside of the timbers; then nail on the ceiling or lining planks. It is impossible if the seams of the outer planks are ever so open, for the vessel to leak; nor can either rats or mice penetrate between the timbers, because they will not touch this composition. Two small brass rollers, or friction wheels, fixed on the opposite side of the pump-spear at the valve, will keep the pump-spear upright, and make the pump work easier. If the editors of the different periodical publications will give publicity to this paragraph, it will be the means of saving a number of the lives of our brave seamen. Europ. Mag. ON HORSE POWER. To the Editor of the Monthly Magazine. SIR, Mr. Wilkes, of Measham, Derbyshire, communicated to the board of Agriculture, in February 1803, the result of an experiment, by which it appears that a horse of the value of 201. drew five tons weight up a rail-road ascending five-sixteenths of an inch in each yard, and that the same animal could not draw more than three tons up a rail rode ascending at the rate of one inch and three quarters. By this experiment it was proved that there was a decrease in the horse's power of 1943-4lb. on the increasing elevation of each one sixteenth part of an inch. This is a species of proof which demonstrates a greater advantage to be derived from reducing the elevation of roads in a billy country, than is shown by the usual mechanical experiments of a carriage drawn up an inclined plane by a weight suspended over a pulley; and it is much more correct, as the physical power of the horse rapidly decreases by the increasing elevation of the hill, at the same time that the load is becoming more difficult to be drawn; but, in the case of the mechanical experiment, weight drawing the carriage continues equally effective. As this is a subject of material importance to the internal trade of this country, it would render a public service if any of your well informed correspondents would be pleased to state, through the medium of your valuable publication, what information they may possess thereon. A. B. To the Editor of the Monthly Magazine. SIR, of Your correspondent A. B., in the last Number of your entertaining Miscellany, after describing the experiment communicated by Mr. Wilkes, Measham, to the Board of Agriculture, in 1803, observes that this is a species of proof which demonstrates a greater advantage to be derived from reducing the elevation of roads in a hilly country, than is shown by the usual mechanical experiment of a carriage drawn up an inclined plane by a weight suspended over a pulley. It appears, by this experiment, that, on the rail-way rising five-sixteenths of an inch to a yard, a horse drew the weight of five tons; but on a rise of one and three-quarter inches to a yard, he could only draw three tons: and A. B. observes, the experiment proves that, there was a decrease in the horse's power of 194 3-4lb. on the increasing elevation of each one-sixteenth of an inch. All this is very true, but it is not by any means a correct statement of the question. No horse can put in motion five tons, or three tons, or one ton, without the assistance of mechanical power; and the advantage derived from the machine, by which he drew the weight of five tons, must be deducted, before any estimation can be made of the power of the horse. A. B. gives no data on which to form such a calculation; but supposing the wheels of the waggon to be thirty inches high, the axles three inches diameter, and well oiled, their power would be equal to about thirtynine-fortieths of the absolute weight, leaving one-fortieth part in friction for the horse to overcome, or 2 1-2 cwt. to which must be added the mechanical power of the inclined plane acting against him: five-sixteenths of an inch VOL. X. is about the 115th part of a yard; therefore the same proportion of the load, which is about 3qrs. 15lb. must be added; making together 3cwt. 1qr. 15lb. which the horse would have to draw up this gentle slope. Now, let us see what the poor beast would have to do up the steeper hill. An inch and three-quarters in a yard is an elevation of about one-twentieth of the length of the inclined plane, and one-twentieth part of the weight of three tons is three hundred weight; this, added to the computed resistance of friction in the machinery, makes 5 1-2 cwt., which the horse had to draw in this case, almost double that of the former; and he must have been a horse of considerable strength and spirit to have exerted himself with such effect. This result seems the very reverse of the inference A. B. is desirous of deriving from the experiment he relates; his position, however, that the physical power of the horse decreases by the increasing elevation of the hill, is nevertheless true. That a horse going up hill is placed in an attitude unfavourable for drawing a load is self-evident, and needs not the aid of mechanical philosophy to furnish proof; but it would be extremely difficult to ascertain in what ratio. It might be cruel to attempt making experiments on the absolute physical strength of animals that cannot express their sensations. I recollect a most inhuman trial of strength of this sort some years ago: a wager was laid whether a race-horse, or a cart-horse, could bear the greatest load; and, by means of a crane, equal weights were heaped upon the backs of each, till the cart-horse sunk under his burthen, while the highblooded animal stood firin and erect. From experiments on the strength of different kinds of wood, made by Col. Beaufoy, it appears that the pitch pine is the strongest wood; next to that the English oak, with straight and even fibres; then the English oak, irregular and cross grained; fourthly, the Riga fir; and fifthly the Dantzic oak. If the strength of the pitch pine be called 1000, the strength of the English oak will be, from the mean of two experiments, 923; of the Riga fir, 782; of the Dantzic oak, 663. Mon. Mag. 33 To give additional strength to iron and steel, Mr. DANIEL proposes to twist the metal in the same manner as strength and compactness are given to hemp and flax. ib. M. LEGENDRE has refuted the objection of Professer Leslie to his beautiful analysis of the relations of triangles. The sum of the three angles of a triangle being a determinate quantity, the sum of two known angles necessarily determines the third-not so the sides, the sum of which are not a determined quantity; consequently the sum of two being known does not determine any thing in regard to the third. We wish professor Leslie had expunged his objection from the new edition of his Elements of Geometry, for the honour of a geometrical mind. ib. The sensations of heat and cold by no means originate entirely from what we call difference of climate; innumerable other circumstances contribute to excite them. Algarotti observes, that when the French king sent some mathematicians to measure a degree under the polar circle, and the king of Spain sent others for the same purpose to the line, to ascertain the true figure of the earth, who would have imagined that those under the equator would suffer most by cold, and those under the arctic circle by heat: and yet this was actually the case. The cold on the summits of the Andes was intense, and the heat occasioned by the length of the polar days was hardly to be borne. Europ. Mag. 1793--13,832,268 5,784,417 1,676,685 1794-16,725,492 8,386,043 25,111,445 1795--16,338,213 8,509,126 24,847,339 1796-19,102,220 8,923,848 28,026,068 1797-16,903,103 9,412;610 26,315,718 1798-19,672,303 10,617,526 30,290,029 1799--24,084,213 9,556,144 33,640,357 1800--24,304,283 13,815,837 38,120,120 1801--25,699,809 12,087,047 57,786,856 1802-26,993,129 14,418,857 41,411,666 1803--22,252,027 9,326,468 31,578,495 1804-25,935,798 10,515,574 34,451,367 1805-25,004,337 9,959,508 34,954,845 1806-27,402,685 9,124,499 36,527,184 1807-25,171,422 9,895,149 34,566,571 1808-26,691,962 7,862,305 34,554,267 1809-35,104,132 15,182,768 50,286,900 1810--34,923,575 10,946,284 45,869,859 1811-24,131,734 8,277,937 32,409,671 1812-31,244,723 11,998,449 45,243,172 The Records of this year were destroyed by fire. 1814-36,092,167 20,499,347 56,591,514 1815-44,053,455 16,930,439 60,983,894 1816-36,714,534 14,545,933 51,260,408 WILLIAM IRVING, Inspector-General of the imports and Exports of Great Britain. Custom-house, London, 13th March, 1817. 1818 PERPETUAL MOTION. Lit. Pan. M. Maillardet of Neufchatel announces, in a foreign Journal, that he has succeeded in solving the celebrated problem of perpetual motion, so long regarded as a scientific chimera. The piece of mechanism to which he applies his principle is thus described:—It is a wheel, around the circumference of which there is a certain number of |