Chapter VII: Front Matter (7)

Pursh and Michaux mention only one species of American _Xanthium_, the _X. strumarium_, while there are three noticed in the catalogue of Dr. Muhlenberg, the above species, and the _X. orientale_, and _X. spinosum_. The first and the last are natives of Europe, and have been naturalized in the United States, with many other plants. The species called _X. orientale_ by Dr. Muhlenberg, appears however to be a native; but the _X. orientale_ of Linnæus, is a native of Siberia, Japan, and the East-Indies; and when plants are found to grow in such opposite quarters of the globe, a strong presumption arises that they are not identical species, which presumption has been confirmed by experience in many instances, whenever the plants of both countries have been accurately examined. Decandolle, in the French Flora, (2d edit, of 1815.) vol. 6. p. 356, describes, under the name of _X. macrocarpon_, a species found in France, and which he takes to be the real _X. orientale_ of Linnæus. He has changed its name, because, he says, that it is not certain that the _X. orientale_ grows in Asia; or, if any grows there, that it is identic with his species; which, however, is really the _X. orientale_ of Linnæus, Son, Lamark, and Gaertner. He adds, that he possesses in his herbarium, a species from Canada, different from his _X. macrocarpon_ which has been figured by Morison, on whose authority some authors have asserted that the _X. orientale_ grew in Canada, mistaking his figure for that plant.

From the above statement, it appears that much obscurity and difficulty arises in botany, when errors creep into the distinction of species: to detect those errors, and to ascertain the synonyme of obscure species, is not one of the least useful botanical labours. Having found, last year and this year, in the neighbourhood of New-York, a species of _Xanthium_ different from any described by the authors, and intermediate between the _X. strumarium_ and _X. orientale_ of Linnæus, I presume that it may be the _X. orientale_ of Muhlenberg, Leconte, and Morison, and the _Xanthium_ of Canada, mentioned by Decandolle, Dumont, &c. I have given to it the name of _X. maculatum_, since the stem is spotted like the _Conium maculatum_. None of those authors having described it, I suppose that its description will be acceptable, and will serve to fix this new species among the American botanists.

Therefore it will appear, that the _X. orientale_, which had been considered as a native of Asia, Europe, and America, is composed of at least three species; the European species, which has been called _X. macrocarpon_ by Decandolle, the American species, which I have called _X. maculatum_, and the Asiatic species, to which the name of _X. orientale_ ought to remain; but which ought to be better described, and more fully distinguished from the _X. macrocarpon_ by those who may chance to meet with it. I even suspect that many species grow in Asia, since that of Ceylon may be different from the Chinese and Siberian species.

_Xanthium Maculatum._

_Definition._ Stem flexuous, round, rough, spotted with black; leaves long-petiolate, cuneate-reniform, nearly trilobe, sinuate-toothed, obtuse, rough, and thick; fruits elliptic, obtuse muricate; thorns rough.

_Description._ The root is annual, thick, and white. The stem rises from one to two feet; it is upright, without thorns, very thick, and with few branches; it is covered with oblong, black, and rough spots. The leaves are few, but large, with very long petiols; they are nearly reniform, with an acute base, and have three nerves; the teeth are unequal, large, and obtuse. The flowers and fruits are disposed as in _X. strumarium_; but the fruits are generally solitary; they are half an inch long, nearly cylindrical obtuse, with the two beaks scarcely perceptible and bent in, covered with short, thick, and rough thorns, rather soft, and not uncinate. The whole plant has a peculiar smell, not unpleasant, somewhat between the camphorate and gravulent odour, but weaker than in _Conysa camphorata_, &c.

_History._ This plant grows on Long-Island, near the seashore and marshes. I have found it common near Bath, on the downs, and in New-Jersey, near Bergen, and Powles Hook, on the margin of marshy meadows. According to Dr. Mulenberg, it grows also in Pennsylvania; Messrs. Torrey and Leconte found it on the island of New-York; and by Morison and Decandolle's account, it is found as far north as Canada. It blossoms in August and September, but the fruits remain on the plant till the severe frosts of December.

_Observations._ This species differs from the _X. macrocarpon_ of Decandolle, by having smaller fruits, without horns, and whose thorns are neither hooked nor hispid; by not having an angular stem, but a round, spotted one, and by its leaves being broader, and not serrate, &c. Nearly all those differences exist between it and the _X. orientale_ of Asia, which has not yet been isolated from the _X. macrocarpon_. The _X. edrinatum_ differs from this by having oval fruits, with aggregated, echinate, and hooked thorns; and the _X. strumarium_, by having cordate hirsute leaves, the fruits aggregated, with hooked thorns and horned tops. The _X. spinosum_, and _X. fruticosum_, ate so totally different that they need not be compared.

ZOOLOGY.

ART. XIII. _Description of the Phalaena Devastator, (the Insect that produces the Cut-worm,) communicated for the American Journal of Science, &c. by_ Mr. JOHN P. BRACE, _of Litchfield, Conn._

This moth, whose larva is one of our most destructive enemies, belongs to the Linnæan family noctua, in the genus phalaena. Its specific characters are as follow: Wings incumbent and horizontal, when at rest; body long and thin; thorax thick, but not crested; head small; eyes prominent and black; antennæ setacious, gradually lessening towards extremities, and slightly ciliated; palpi two, flat, broad in the middle, and very hairy; tongue rolled up between them, not very prominent; clypeus small, legs long, small and hairy; wings long as body; under wings shortest; colour a dark silvery gray, with transverse dotted bands of black on upper wings. The insect lays its eggs in the commencement of autumn, at the roots of trees and near the ground: they are hatched early in May. The habits of the cut-worm have been often and fully detailed. They eat almost all kinds of vegetables, preferring beans, cabbages, and corn. They continue in this state about four weeks; they then cast their skin and enter the _pupa_ state, under ground. This is a crustaceous covering, fitted to the parts of the future insect. In this they continue for four weeks longer, and come out in the fly, or insect state, about the middle of July. All those chrysalids that I exposed to the sun, died; and all those that were kept cool under earth, produced an insect: hence I infer, that the heat of the sun will kill the chrysalids. If, then, the ground be ploughed about the first of July, many of those insects might be destroyed, and the destruction of the productions of the next year prevented; for the _pupa_ is never more than a few inches under ground.

The phalaena devastator is never seen during the day; it conceals itself in the crevices of buildings, and beneath the bark of trees. About sun-down it leaves its hiding-place, is constantly on the wing, and very troublesome about the candles in houses. It flies very rapidly, and is not easily taken.

Such is the description of this formidable enemy to vegetation. No efficacious method has yet been taken to prevent its ravages, but the one who could accomplish it, would do the cause of agriculture an essential service.

ART. XIV. _Description of a New Genus of North American Fresh water Fish, Exoglossum, by_ C. S. RAFINESQUE, ESQ.

Mr. Lesueur has published, in the 5th Number of the Journal of the Academy of Sciences of Philadelphia, for September, 1817, the description of a new fish, which he calls _Cyprinus maxillingua_: he considers it as a very singular and anomalous species, owing to the peculiar structure of its lobed lower jaw and tongue, which is external, and situated as an appendage to the former. It was discovered in Pipe-creek, Maryland, in June, 1816, by said author, who confesses that he does not consider it as properly belonging to the genus _Cyprinus_, and presumes that when other species shall be discovered, possessing the same character, they will constitute a separate genus. Although this principle and presumption is correct, it was wrong to delay the formation of such a distinct genus, because only a species was then known, since so many genera are composed of single species. However, Mr. Lesueur's expectation was verified even before he wrote it, since in May, 1817, I had discovered in the Fishkill, State of New-York, another, species, evidently congenerous with the _Cyprinus maxillingua_, having the same structure of the mouth, &c. I therefore venture to establish a separate genus for those two species, having no doubt that many more will hereafter be added to it by accurate observers, and I give to it the name of _Exoglossum_, meaning _outside tongue_. It will belong to the same natural order and family of the genera _Cyprinus_, _Catostomus_, &c.

EXOGLOSSUM. _Generic Definition._--Body oblong, thick, and scaly; head without scales, mouth without lips or teeth, upper jaw longer, entire; the lower trilobed, middle lobe longer, performing the office of tongue; dorsal fin opposite to the abdominal fins; three rays to the branchial membrane.

_Remarks._ Besides the above characters, the two species known at present have, in common, the lateral line ascending upwards at the base, the tail forked, &c.

1. Species. _Exoglossum vittatum_, Raf. _Cyprinus maxillingua_, Lesueur. _Specific Definition._--Back brownish olive; sides blue, with a brownish band; a black spot at the base of the caudal fin, lower parts silvery gray; lateral line ascending upwards at the base; dorsal and anal fins with nine rays; tail forked.

_Remarks._ Length four inches; vulgar name _little sucker_. For further particulars, see Lesueur's description, p. 85. cum. ic. I have been obliged to change the specific name of _maxillingua_, since it has the same meaning as the generic name.

2. Species. _Exoglossum annulatum_, Raf. Head black above, cheeks and gills olivaceous, back blackish olive, sides olivaceous, lower parts olive gray; a black ring at the base of the tail; lateral line ascending upwards at the base, tail forked, dorsal and anal fins with nine rays.

_Remarks._ Length from three to six inches; vulgar name, _Black chub_. Head broad and flat above, iris large and gray; fins olivaceous, abdominal distant and with nine rays, pectoral with fifteen, caudal with twenty-four.

PHYSICS, MECHANICS, AND CHEMISTRY.

ART. XV. _On the Revolving Steam-Engine, recently invented by_ SAMUEL MOREY, _and Patented to him on the 14th July, 1815, with four Engravings_.

_To Professor Silliman._

SIR,

The successful employment of the steam-engine, in navigating the rivers and inland waters of the United States, and the probable extension of this mode of conveyance of persons and property, makes those improvements desirable which adapt the steam-engine to this purpose with less complication and expense, placing it more within reach of individual enterprise, and rendering it even useful on our small rivers and canals.

The steam-engine, though often seen in operation, is not readily understood by an observer, without an acquaintance with the facts in natural philosophy on which its power depends: and it may elucidate the subject of this communication to advert, for a moment, to the gradations by which this important machine has attained its present perfection.

It will be recollected that as early as 1663, the Marquis of Worcester published some obscure hints of a mechanical power derived from the elastic force of steam.

In 1669, Savary, availing himself of the suggestion, and pursuing the subject more scientifically, invented his engine, consisting of an apparatus to cause a vacuum by the condensation of steam, so that the water to be raised would thereupon, by the external weight of the atmosphere, rise into the chamber of the apparatus, which the steam had occupied.

As caloric becomes latent in the steam which it forms at 212° of Fahrenheit, and the steam thus formed occupies 1800 times the bulk of the water composing it; and as it returns instantly to a state of water on losing its heat, by contact with any thing cold, Savary easily produced his vacuum by the injection of a little cold water.

He also used (though in a very disadvantageous manner) the expansive force of steam to drive the water out of the chamber, through a pipe different from that by which it entered.

It is doubtful whether this kind of engine was ever erected on a scale of any magnitude; for, a few years later, Newcomen and Crawley invented the first engine with a cylinder and piston; and Savary, abandoning his own, united with them in bringing their engine into use.

As steam drives out air, the principle of this engine was to let steam into the cylinder beneath the piston, where (the piston having risen to the top of the cylinder) a jet of cold water[22] condensed the steam, produced a vacuum, and the piston, working air tight, descended by the pressure of the atmosphere upon it, this pressure being a weight of nearly fifteen pounds to each square inch; so that if the cylinder were two feet diameter, it would amount to a weight of three tons.

This mode of operation prevailed for about fifty years, and though much used to pump water from mines, was found to have great inconveniences and defects; till, in the year 1762, Mr. Watt, being employed to repair a working-model of an engine at the University of Glasgow, was led to direct his mind to the improvement of the machine; and from his experiments sprung the most essential change, viz. the condensation of the steam in the cylinder, by opening a communication with a separate vessel, into which the injection of cold water was made, thus allowing the cylinder to remain hot.

On opening that communication, the steam instantly rushes to the cold, or rather is destroyed by the instant loss or reduction of its heat, and the vacuum thus made allows the piston to descend as before mentioned.

Mr. Watt soon added the airpump to the condenser, to extract the air extricated from the water in boiling, together with the water injected.

The next step was to close the upper end of the cylinder, the piston-rod working through a tight packing to exclude the air, letting the steam in above, as well as below the piston, by an alternate communication, and then condensing it in both cases alternately, thus producing a double stroke; at the same time deriving some aid from the expansive force of the steam on the side of the piston opposite to the vacuum. This is essentially the form of all the engines in use at the present day. The minor parts devised by Mr. Watt, as the working of the valves, &c. were such as would readily occur to a scientific mechanician.

While he was bringing the engine to its present perfection, and furnishing it for the numerous mines, manufactories, and breweries in Great Britain, variations were devised by Cartwright, by Hornblower, Woolf, and others in England, and more recently by Evans and by Ogden in America, evincing much ingenuity, but (with the exception of Evans's, which is a simple engine of high pressure) making the machine more complex.

Watt and Bolton's engine, as most generally used, being properly an atmospheric engine, or working with steam so low as merely to produce a vacuum in the cylinder, became of enormous dimensions, when the power required was that of an hundred horses: a scale of estimate adapted to the comprehension of those who had before used the labour of that animal, and preferred to substitute the steam-engine.

It had not, however, escaped the notice of Mr. Watt, that there existed in steam another source of power besides that of atmospheric pressure. The experiments of his learned friend, Dr. Black, of Glasgow, as well as those of the French chemists, and of Papin, in the instance of his digester, had ascertained the laws of its expansive force, and amongst other interesting facts, those subservient to our present purpose; viz. That after water has reached the boiling point, 212° of Fahrenheit, the caloric which enters it no longer becomes latent, but sensible in the steam, which thereupon acquires expansive force to an unlimited degree: that this force increases geometrically; or, that every accession of about 30° of heat, nearly doubles its power at those stages of progression; that when the pressure at a high temperature is taken off, or the steam allowed to flow, there is an instantaneous and rapid production of steam; a fact which proves there can be no necessity of a large space for the steam to form in above the water, provided it be sufficient to prevent water from issuing with the steam, and, therefore, that boilers of a small cylindrical form are best.

It may be a fair question, why Mr. Watt did not further employ this principle of expansive force? We may readily conceive of several motives to the contrary. Watt and Bolton's engines were in great demand; they gave entire satisfaction, and the work they performed saved so much labour as to afford the purchase at a high price. The public had gained immensely by this better form of the engine, and Mr. Watt enjoyed the benefits of the patent he had obtained; and, at a later period, this preference was increased by an accident which happened to Trevethick's engine, though caused by gross mismanagement, that would have been equally fatal to any other.

From an investigation, by a committee of parliament, into the causes of the several fatal explosions of steam-engine boilers within a few years, published in Tillock's Magazine, vol. 1., it appears that in every instance the accident was fairly attributable to neglect or mismanagement. Many competent persons were summoned to give their opinions; and through the contrariety of their testimony, the prevalent opinion appears to have been, that cast-iron boilers cannot be safe; that as many engines of high steam as of low are now used in England, but that the high are much the most economical in fuel and cost; that they are more safe, if properly constructed; it being argued by some, that boilers for steam of 100 pounds to the inch, are easily made of strength to sustain 500 pounds; this excess being much greater than in those constructed for low steam, makes them comparatively the safest, as the safety valves are less liable to be accidentally prevented from venting the steam.

In the United States, instances are not wanting of the successful operation of high steam; of which the engine at the mint is a conspicuous example. There can, indeed, be no good reason why this great power should not be employed to an extent within the limits of safety, if more economical and convenient. If boilers can bear (as they are usually made of iron) 500 pounds, there can be no danger in using them with fifty; and this gives an increase of power, with a condenser, fourfold, or makes a ten horse power forty. The economy, therefore, of high steam, hardly admits of a question. It seems unphilosophical to neglect a power so great, merely because it is so.

Mr. Watt was desirous of an improvement by which to obtain a direct rotatory motion. His experiments, resembling those of Curtis, at New-York, were not found permanently practicable.

It was probably perceived to be a great object to get rid of a reciprocating movement of large masses, on the well-known mechanical principle, that it consumes power to check momentum, as well as to give it--to drag an inert mass into motion rapidly, in opposite directions. And in engines for navigation this is more disadvantageous than for land uses, as the foundation of the engine cannot be perfectly substantial.

An engine, therefore, that possesses the cylinder and other members of Watt's engine, working with or without a condenser, at pleasure--having a rotatory movement--requiring no ponderous balance-wheel--adapted to high steam--attended by no inconvenience from the rapidity of its stroke or movement--having no inert mass of machinery to move reciprocally--more powerful, proportionately, from its using steam as strong as that in the boiler--of a simple and durable construction, and by a combination of two similar machines attached to the same common intermediate axis, operating so as to give nearly an equal power at every moment of its operation, seems to combine every thing desirable in an engine for the purposes of navigation. Such appears to be the revolving engine invented by Mr. Morey.

When those who are acquainted with steam-engines of the atmospheric kind only, are told that Morels cylinder revolves, their imaginations may suppose a moving mass as large as the enormous cylinders they have been accustomed to see: but it is not so; the elastic force of steam requires machinery but of comparatively small dimensions.

The revolving engine makes up in activity what in other engines is supplied by magnitude.

We will take for example the engine working at the glass manufactory, in this vicinity, the cylinder of which has one foot stroke and nine inches diameter, and is at least a ten horse power, working with fifty pounds--or, the engine now building for the Hartford boat. This engine will have two cylinders of seventeen inches diameter and eighteen inch stroke; they will revolve fifty times a minute. The area of the piston in each being 227 inches, steam at fifty pounds will give an hundred horse power.

This boat is seventy-seven feet long, twenty-one feet wide, and measures one hundred and thirty-six tons. The engine, with its boilers, will occupy sixteen feet by twelve, or one-eighth only of the boat; the cylinders being hung on the timbers of the deck over the boilers. She is principally intended to tow vessels up the river to Hartford.

In towing, it is of importance that the engine admit of any inferior velocity or power, till some momentum is had. An engine working by atmospheric pressure does not admit of this. And as the boat herself, at the moment of commencing the operation, may have no steerage-way, by placing two blade-rudders at the sides, behind the water-wheel, where a current is occasioned by them, the boat is kept in her relative position.

The application of the steam-engine to the towing of other vessels was fully appreciated by the late Mr. Fulton, whose conspicuous labours and enterprise, in the establishment of steam-boats, the public duly honours. His active mind had conceived of its utility; and he would have obtained a patent, had not the previous employment of steam in this way, and the award of arbitrators on the question been in my favour; which I mention merely in reference to the supposed utility of this mode of operation, in connexion with Morey's engine.

Morey's engine should rather be denominated a revolving engine than a rotatory one, especially as it is essentially different from one so called invented by Mr. Curtis.

Plate I. Fig. 5, represents the arrangement of a double engine for a boat, with its cylinders in different positions. _a a a_, boilers; _b b_, tar-vessel; _c_, valve-box; _d_, cylinders in different positions; _e_, piston-rod; _f_, pitman; _h_, centre-piece; _i i_, shaft; _k_, valve; _l_, steam-pipe; _m_, escape-pipe; _n_, condensers; _t_, water-wheel; _v_, face of the valves; _x_, tar-fire. The frame, holding the cylinder (_d_) is, by its opposite sides, so hung as to revolve. To the end of the axis of one side, extended over the cylinder, is fixed the centre-piece (_h_) resembling a crank, from which the bar or pitman (_f_) communicates to the cross-piece of the piston-rod. On this same axis, but outside the frame, is placed two circular pieces, one of brass, the other of iron, (_k_) which we may call the valves. One is fixed on the axis, the other moves, and accompanies the frame and cylinder in its revolution; from it, at opposite sides, pipes lead the steam to each end of the cylinder. It has a smooth face, which applies, and is kept by springs close to that of its counterpart fixed on the said axis. Steam-pipes lead from the boilers through the counterpart into the moving valve. On the opposite side of the fixed piece the eduction-pipe (_o o_) leads to the condensers.

The condensers (_p_) are upright vessels, two to each cylinder, connected at top by a sliding valve box, so that the steam enters them alternately. At bottom are two valves, kept closed by weights. A stream of water is injected into the condensers, which escapes by the bottom valves (_p p_) by which also the air is blown out, at every stroke, in the same manner the engine is cleared of air at first.

There are also two cocks and cross-pipes seen, Plate III. Fig. 4, to change the steam from one side to the other of the valve, to give a reversed motion of the engine.

The power is communicated to its object from the opposite side of the frame by the axis attached thereto, and supported on bearings. This axis (_i i_) may be of any length; may terminate in a crank or cog-wheel, or another cylinder (as here represented) may be attached thereto at right angles to the first, to co-operate and produce, at every moment, equal power.

Plate II. Fig. 6. Profile of the above. _a a_, the boiler; _c_, valve; _d e g_, cylinder and frame; _f_, valve; _h h_, cog-wheels; _i_, cog-wheels to move the pumps; _k k_, condensers; _m m_, coverings in; _o o_, gas-fire flue.

Fig. 1. _a_, steam-pipe; _b_, escape-pipe; _c_, fixed valve; _d_, moving valve; _e_, axis; _f_, a washer; _g_, section of frame; _h_, a washer; _i_, centre-piece; _l l_, steam-pipe; _k k_, springs to keep the valves together.

The canal-boat has her wheel in the stern. (See Plate IV.) The motion is given by a cog-wheel upon its axis (_g_) played upon by another, upon a shaft, at right angles, to which the engine communicates motion. The wheel being divided by a space of two or three inches, into two parts, to allow room for this shaft, and for the support of its end.

Fig. 3, represents the arrangement of the machinery, occupying the after-part of the boat. An engine of twenty horse power may thus occupy half a canal-boat, can tow a number of others at such rate as may be proper on canals.[23] _b b_, the boilers; _c_, tar-vessel; _d_, the cylinder; _f_, water-wheel.

The supply of water to the boilers is either by a pump, in usual form, or by the _supply-chamber_ of my invention, (Plate III. Fig. 2.) which consists simply of a pipe having two stop-cocks, one end in a reservoir, the other opening into the boiler at top, sloping downward for a foot or two. The cocks are in the sloping point. The operation commences, by opening the cock nearest the boiler, the steam drives the air out of the pipe through the water into the reservoir; shut the cock, and the water rises from the reservoir to fill it; shut the second cock, and open the first, the water discharges from the chamber into the boiler; repeated by a movement from the engine, when in motion, the supply continues with more certainty than by a pump, because it is difficult to pump hot water, on account of the elasticity of the steam arising from it, which obstructs the operation of the valves. And it is important not to have to pump against the pressure of high steam.[24]

Plate III. Fig. 4. The mode of changing the passage of the steam to the opposite sides of the valves, in order to get a reversed motion of the engine. _a a_, the fixed part, or valves; _c d_, the pipes; _f g_, the cross pipes; _e e_, the cocks, which are represented open, to pipes _c_ and _d_--turn them half round, they close _c_ and _d_, and open _f_ and _g_. Fig. 1 shows the side-rudders, _d_, _e_, &c.

To this engine is conveniently applied the gas-fire, in the following manner.

The boilers being cylindrical, with an inside flue for fuel, two or three are placed close together, and set in the following manner: First, cross-bars of iron are laid on the timbers, a platform of sheet-iron is laid on these bars, coated over with clay mortar, or cemented, to keep out the air. Upon the sheet-iron, and over the bars below, are placed cast-iron blocks in shape to fit the curve of the boiler, so as to raise it three or four inches above the platform. The sheet-iron is continued up the outsides of the outer boilers, so as to enclose them; and at one end, between the boilers, there are small grates for coal or other fuel.

The tar vessel or vessels, as the case may be, are lodged in the space between and upon the boilers, and a small fire may be made under them, if necessary. A pipe leads steam in at one end, two pipes at the other; one near the bottom, and one near the top, lead out the tar and steam. These pipes unite below; the steam and tar, thus mingled in suitable proportions, flow to the main fire, or the flues of the boilers, as well as to the coal-fire below, where the gas and tar are ignited. The fireman judges of the proportion of each, by the effect; the object being to produce a nearly white flame without appearance of tar. Thus flame is applied to the greatest possible surface, and the apparatus adds very little to the cost of the engine.

There are also two improvements in the boiler, which I deem it important to mention. First, the lining or covering of the flue within with sheet-iron or copper, _perforated with small holes_, reaching down its sides, nearly to the bottom. Plate III. Fig. 2. _a_ the boiler; _b_ the flue; _d_ the grate; _c c_ the lining.

This causes the water to circulate rapidly between them to the top of the flue, and protects it from being run dry, or heated red hot, when the water gets, by accident, too low. The lining also _causes the steam to form much faster, in consequence of this circulation_.

The other is the interior boiler. A vessel occupying the back part of the flue. Plate II. Fig. 8. (_d_) communicating downwards with the water, and upwards with the steam of the main boiler. The fire acts upon it very forcibly, surrounding it on all sides.

I have said there is no reciprocating movement in Morey's engine. Should it be objected that the piston moves in the cylinder as usual, it must be apparent that it also moves circularly; it is in fact the cylinder that moves, carrying the piston with it, which gives and keeps up the motion, by drawing and pressing on the centre-piece, and communicating the resistance thence to the _guides_ of the cross-piece on the insides of the frame, which thus receives its motion.

In fact, this form of the engine seems divested of all the usual drawbacks on its power, and leaves it to act freely with any velocity, according to the strength of the steam in the boilers.

Such it appears in principle, and such thus far in practise. I have therefore preferred it for the purposes of navigation, and have purchased the patent right. But, though interested to recommend it, I cannot expect it to be preferred by the intelligent, if there is not merit in the invention, and great economy in its use. It may be considered the most direct application of the power, and the most unexceptionable mode of using the expansive force of high steam. And from the nature of its movement the most applicable to boats and vessels.

Your Journal being the intended medium of information to promote the useful arts, I hope it may be consistent with this object to explain the manner in which these improvements may be made extensively useful.

It being necessary to supply the engines at a reasonable rate, I have established a manufactory for this kind only. The great expense of steam-boats hitherto, has confined their use too exclusively to the accommodation of passengers. There is a wide field opening for their use, in freighting, on all our waters; and it is often of importance to a community, when great savings can be made, that large capitalists should be induced to engage that such savings may be greater. Where companies are formed for an extensive operation, the legislature may, with propriety, grant an extension of the time for patents to run, that such persons may be duly remunerated for their enterprise, by the duration of the service.

Our laws do not yet make a proper distinction between patents of a large and expensive kind and those requiring little or no capital to go into operation. The period of fourteen years remunerates the inventor of those improvements only that require no capital, and involve no risk.

On this ground several of the State legislatures have, with good policy, given encouragement to this kind of enterprise. They suspend the free use of the invention a few years, rather than loose its immediate operation on a large scale of public benefit.

The constitutionality of the measure plainly appears by its not interfering with the laws of the United States. It is not an act exclusive of, or in opposition to, patents, but acknowledging and confirming them. It is furthering and giving effect to the intentions of the general government, in the encouragement of useful inventions. For their own particular section of the union, a State legislature may thus provide for the protection of capital, engaged in enterprise of uncommon risk, as well as of uncommon usefulness, without excluding other and better inventions, should they arise.

I shall ask leave to communicate, for some future Number, the results of experiments, now making, with the gas fire applied to engines.

I am your most respectful humble servant,

JOHN L. SULLIVAN

ART. XVI. _Cautions regarding Fulminating Powders._

_Fulminating Mercury._

During a late lecture in the laboratory of Yale College, a quantity of fulminating mercury, probably about 100 or 150 grains, lay upon a paper, the paper lay on a small stool, which was made of pine plank, _one inch and a half thick_; a glass gas receiver, 5 or 6 quarts capacity, stood over the powder, as a guard, but without touching it, and stool and all stood on one of the shelves of the pneumatic cistern, surrounded by tall tubes and other glasses, several of which were within 6 or 8 inches. A small quantity of the fulminating powder, at the distance of a few feet, was merely flashed, by a coal of fire, but without explosion. In a manner, not easily understood, the whole quantity of powder under the large glass instantly exploded with an astounding report; _but the glass was not exploded_--it was merely thrown up a little; in its fall it was shattered, and broke a glass which it hit, but no fragment was _projected_, and none of the other contiguous tubes and glasses were even overset, nor were any of a large audience, and some of them very near, even scratched; _but the plank, one and a half inch thick, on which the powder lay, had a hole blown quite through, almost as large as the palm of one's hand_. This is a striking instance to prove that the _initial_ force of this powder, when exploded, is very great, but that it extends but a very little way. If it be strewed through a glass tube of three-fourths of an inch in diameter, and exploded by a coal of fire or hot iron, the tube may be held in the naked hand, and the powder only flashes without breaking the tube, and merely coats it over inside, and that very prettily, with the revived quicksilver.

_Fulminating Silver._

Chemists are too well acquainted with the tremendous energy of this preparation, to make any comment upon its powers necessary. Unhappily, however, it is now made a subject of amusement; it is prepared for sale by those who know nothing of it, except as a nostrum, and it is bought by others who have not even this degree of knowledge. It is true it is put up in small quantities, in the little toys called torpedoes, and, if exploded one by one, they will ordinarily do no harm; but as they fall into the hands of children, we can never be secure that they will be discreetly used.

A very severe accident, from the unexpected explosion of this substance, occurred some years since in the laboratory of Yale College. (See Bruce's Journal, Vol. I. p. 163.) And, notwithstanding that this occurrence was well known in New-Haven, the same accident, only under a severer form, has again occurred in that town.

A man who had bought the secret of making fulminating silver, had prepared as much as resulted from the solution of one ounce and a half. Apparently, in a great measure, unaware of the nature of the preparation, he had placed it, unmixed with any thing, on an earthen plate, which stood on a table; his wife and children being around, he sat down to distribute the powder upon several papers which he had prepared for the purpose; sand and shot are mixed with the powder in the papers for the purpose of giving momentum, and of producing attrition when the torpedo is thrown, in order to ensure its explosion. Probably also the sand, looking not very unlike the powder, may be intended to screen it from view, and thus to preserve the secret, should the papers be opened. The unhappy man no sooner touched the fulminating silver with a knife, than it exploded with its usual violence; the table was split in two; blood issued copiously from every part of his face, not from wounds, for it does not appear that the fragments hit him, but, according to the opinion of a competent judge, the blood was actually forced through the pores of the skin by the power of the explosion, which very nearly destroyed his eyes. He suffered immensely, but now, at the end of eight months, sees partially with one eye, but the other is nearly, if not quite, destroyed.

Should not the tampering with such dangerous substances by ignorant people be prevented by law?

In a late lecture in the laboratory of Yale College, some fulminating silver, on the point of a knife, was in the act of being put upon a copper-plate connected with one pole of a galvanic battery in active operation, the other pole was not touched by the experimenter; but it seems that the influence which was communicated through the floor of the room was sufficient instantly to explode the powder, as soon as the knife touched the copper-plate; the knifeblade was broken in two, and one half of it thrown to a distance among the audience.

Recently also, we are informed, in one of the foreign journals, that a man in England, who accidentally trod on a quantity of fulminating silver, had his foot nearly destroyed by the explosion.

USEFUL ARTS.

ART. XIX. _Account of an economical method of obtaining Gelatine from bones, as practised in Paris. Communicated to the Editor by Mr._ ISAAC DOOLITTLE.

_Paris, 16th May, 1818._

MY DEAR SIR,

A few days since I visited the very interesting establishment of M. Robert, for the extraction of the gelatinous matter from bones.

The bones used for this purpose are those only which answered no useful purpose (except for the fabrication of phosphorus or ammoniac) before this discovery, such as those of the head, the ribs, &c. &c., the legs of sheep and calves, &c. Those formerly used by _toysmen_ (_Tabletiers_) are still used for that purpose, after extracting so much of the gelatine as can be done by ebullition.

When the heads of oxen are to be operated upon, they begin by extracting the teeth, (these are reserved for the fabrication of ammoniac, as affording a greater proportion of that alkali than any of the other bones,) they then break the skull, in such manner as to preserve all the compact parts in as regular forms as possible; these pieces present a surface of 20 to 30 square inches, and are put to soak in a mixture of muriatic acid and water. The muriatic acid used bears about twenty-three degrees o£ the _aeromètre_, and is diluted by water to about six degrees--four parts of the liquor is used to one part of bones. They are left in this state, in open vessels, until a complete solution of the phosphate of lime has taken place, and the gelatinous part of the bone remains in its original shape and size, and is perfectly supple. When this operation is finished, which commonly lasts six or eight days, the gelatine is put into baskets, being first drained, and immersed a short time in boiling water, in order to extract any small remains of grease, which would deteriorate the gelatine, and also to extract any of the acid which might be lodged in the pores. It is then carefully wiped with clean linen, and afterward washed in copious streams of cold water, to whiten it, and render it more transparent; it is then put to dry in the shade.

Two ounces of this gelatine are said to be equal to three pounds of beef in making soup--that is, three pounds of beef and two ounces of gelatine will make as much soup, and of as good quality, as six pounds of beef. It is constantly used in some of the hospitals of the capital, particularly in the lying-in-hospital.

The ends of the bones, and such parts as from their porosity might still retain a portion of the acid, are separated, and used for making glue of a very superior quality.

The inside of the bones of sheep's legs furnish a sort of membranous glue, which supplies, with advantage, the place of isinglass in the fabrication of silk stuffs.

I give you these particulars, not because I think they contain any thing new to you, _in principle_, but because I may have hit upon some _details_ with which you were unacquainted.

ART. XX. _Experiments made in France upon the Use of Distilled Seawater for domestic purposes, and its Effects on the Constitution, when taken as a Beverage._[25]

In consequence of the great want of good fresh water in many of the maritime parts of France, the government some time since ordered some experiments to be made, upon an extensive scale, in order to ascertain how far seawater, when distilled, could be used with success. Little or no use had hitherto been made of water so prepared, except in long voyages, and chiefly then only as a matter of necessity. There are above two hundred leagues of seacoast in France, where, to the breadth of many miles, the inhabitants are compelled to make use of bad and impure water, which, in many cases, is injurious to the health of themselves and their animals. In similar cases, it was the custom of the ancients to construct cisterns; but these are not only expensive in themselves, but their utility depends upon the quantity of rain that falls; while upon the shores of the most barren places, nature has supplied a variety of vegetable matter, which, when dried, would not only serve as a fuel for the purposes of distillation, but from the ashes of which might be obtained a saline substance, sufficient to repay the expense of collecting, drying, and burning. Thus the fuel for the distillation of seawater would, in reality, cost nothing, while its preparation would employ many individuals, particularly women and children. Before, however, erecting any apparatus for this purpose, it was necessary to ascertain both the utility and salubrity of the water thus prepared.

It is well known that Bougainville, Phipps, Homelin, &c. had employed this water with much success; but they, like most of the chemists of the last age, did not endeavour to imitate the process of nature in all its simplicity, but mixed various substances with the seawater, in order to take away or lessen the effect of the empyreuma arising from the distillation, and which was so unpleasant to the smell and taste. And it is this which in general renders sailors so averse to it, and excites a prejudice very unfavourable to the salubrity of distilled seawater. One of the great objects to be ascertained was, whether this disagreeable smell and taste was peculiar to seawater or arose from the act of distillation.

In the month of July, last year, the king ordered some experiments to be made, upon a large scale, at the three ports of Brest, Rochefort, and Toulon. The instructions given were as follows: That a sufficient quantity of seawater should be distilled to prepare, for the space of a month, bread and other food for a certain number of criminals, who were employed on the works of these ports, and also to supply them with drink, keeping from them during that period every other liquid. Ten or twelve persons at each part voluntarily came forward and offered themselves for the experiment.

The persons employed by government first distilled a sufficient quantity of seawater, without the admixture of any other substance. This produce dissolved soap, dressed vegetables, produced the same appearances, with the aerometer, as that distilled from spring water. There was no difference between the one and the other. But the distilled seawater had always that empyreumatic taste and smell, of which we have before spoken; and it was so strong, that the commission at Toulon called it _odeur de marine_, and _odeur de marecage_. But this is not peculiar to seawater, for the result of a distillation of fresh water had always the same taste and smell. Neither of these liquids immediately loses this by being filtered through charcoal; but by being exposed for some time to the air, the distilled seawater loses this unpleasant quality, and then it does not differ from fresh water derived from the purest source; and both have equally stood every chemical test to which they have been exposed. The chemical properties of this water having thus been determined, it remains to give an account of the effects upon the individuals who underwent the experiment. These are the principal results:

_Brest._ During the first days, those who drank the water complained of a weight upon the stomach. This indisposition, which was the only one they experienced, soon decreased upon taking exercise, and totally went off by an additional ounce of biscuit added to their common ration. One of them, on the 29th day, had a few symptoms, but which he himself attributed to an indigestion, from some bacon he had eaten. Eight individuals drank twenty-five pints a day, rather more than three pints each,--(N. B. The French pint contains very near fifty-seven cubic inches of English measure, and is the regulation size for the claret or Bordeaux bottle; but in general the bottles are rather smaller. The French pint is therefore equal to rather more than nineteen-twentieths of an English quart, wine measure.)

_Toulon._ The results obtained at the arsenal of this town, were not less decisive or satisfactory. The six persons who made the experiment acquired a greater degree of freshness in their appearance, and were much fatter. Their daily consumption of distilled water was nine pounds (_poids de marc_) for drink, and eleven pounds for cooking. This is nearly the same relative quantity as those at Brest.

_Rochefort._ The experiments here have not been made with the same regularity; because the fifteen persons fixed upon had all agreed to say that they were very ill. The two principal ones complained of violent cholics and diarrhœas: but the plot was discovered, and upon being put upon the sick-list, (_à la diète_,) they were laughed at by their companions. No one of them was really indisposed; on the contrary, many thought they experienced some good effect in regard to some infirmities under which they had long laboured.

The above are not, however, the only experiments which have been made upon this beverage. Several persons wishing to ascertain its effects by individual experience, have voluntarily confined themselves to its use; and the members of the commission of inquiry are almost in the daily practice of taking it. The captain of the Duclat has taken it every day at his meals for twenty days, and has experienced not the smallest inconvenience from its use. M. M. Vasse, and Chatelain, apothecaries to the marine at Brest, have occasionally kept the water in their mouths for four hours, by constantly renewing it, and have not found either the sharp taste, or other caustic qualities, which have been said to be peculiar to it. And here it may be proper to state, that the mouths of all the individuals who had taken the water for a length of time were examined, without the detection of any thing in them either of a swollen or inflammatory appearance. Such are the reports of commissioners employed to investigate the effects of distilled seawater, who, although separated at a great distance from each other, and having no communication, all agree in the inference, that it may be employed without any injury to the health, both as a beverage and in cookery, for the space of at least a month; and the fair presumption is, that it may be employed for a much longer time; and that in consequence, it must be considered as a very happy resource in long voyages of discovery.

FINE ARTS.

ART. XXI. _Essay on Musical Temperament. By Professor_ FISHER, _of Yale College_.

[_Concluded from page 35._]

PROPOSITION V.

To determine that position of any degree in the scale, which will
render all the concords terminated by it, at a medium, the most
harmonious; supposing their relative frequency given, and all the
other degrees fixed.

The best scheme of temperament for the changeable scale, on supposition that all the concords were of equally frequent occurrence, is investigated in Prop. III. But it is shown, in the last Proposition, that some chords occur in practice far more frequently than others. Hence it becomes necessary to ascertain what changes in the scale above referred to, this different frequency requires. Any given degree, as C, terminates six different concords; a Vth, IIId, and 3d above, and the same intervals below it. Let the numbers denoting the frequency of these chords below C be denoted by _a_, _b_, and _c_, and their temperaments, before the position of C is changed, by _m_, _n_, and _p_: and let the frequency of the chords above C be denoted by _a′_, _b′_, and _c′_, and their temperaments by _m′_, _n′_, and _p′_, respectively. If, now, we regard any two of these 6 chords, whose temperaments would be diminished by moving C opposite ways, and of which the sum of the temperaments is consequently fixed, it is manifest that the more frequent the occurrence, the less ought to be the temperament. Were we guided _only_ by the consideration of making the aggregate of dissonance heard in them in a given time, the least possible, we should make the one of most frequent occurrence perfect, and throw the whole of the temperament upon the other. Let, for example, _a_ be greater than _a′_, and let _x_ be any variable distance to which C is moved, so as to diminish the temperament _m_, of the chord whose frequency is expressed by _a_. Then the temperament of _a_ will become = _m_ ~ _x_, and that of _a′_ = _m′_ + _x_. Hence, as the dissonance head in each, in a given time, is in the compound ratio of its frequency of occurrence and its temperament, their aggregate dissonance will be as

a · (m ~ x) + a′ · (m′ + x);

a quantity which, as _a_ is supposed greater than _a′_, evidently becomes a minimum when _x_ = _m_, or the chord, whose frequency is _a_, is made perfect. But in this way we render the harmony of the chords very unequal, which is, cæteris paribus, a disadvantage. As these considerations are heterogeneous, it must be a matter of judgment, rather than of mathematical certainty, what precise weight is to be given to each. We will give so much weight to the latter consideration, as to make the temperament of each concord _inversely as its frequency_. We have then

a : a′ :: 1/(m - x) : 1/(m′ + x);

which gives x = (am - a′m′)/(a + a′).