of carbonic acid gas; that the leaves absorb car-ever, is, that while we observe in the productions In this epidermis Saussure has pointed out a It is more considerable as the plant is more vi gorous. leaf. For the discovery chat leaves have the property of absorbing carbonic acid gas from the atmosphere, we are indebted to Dr. Priestley, whose name reflects such lustre upon his country, and fills so large a space in the iterary world. This gas, as we learn from Saussure, is essential to vegetation; for plants will not connue to grow in air totally deprived of carbonic acid gas. growth of plants in pure water exclusively? Why do parasitical plants possess properties different from those vegetables on which they grow? And in what manner are we to explain the vegetation of lichens and mosses upon naked rocks and stones? The experiment of Van Helmont, to which I have alluded, is this: a willow of a certain weight was planted in an earthen vessel, containing a determithis truly admirable reciprocity of service, is always nate quantity of soil. This willow, for the space of preserved that equilibrium which reigns throughout five years, he watered with distilled water. At the the constituent principles of the atmosphere. end of that period, having weighed the willow, he Flants, vegetating in the dark,exhibit a blanch-found it to have received a very considerable auged appearance; but when exposed to the light, mentation of weight, and the earth to have lost but they are robed in green. Unaided by the influ- little. Hence the conclusion is irresistible, that it ence of this luminous fluid, the vegetable world was the water and not the earth which served for would no longer present those beautiful shades with the nutrition of the plant. The rapid and widewhich it is enriched. No more would bloom the spread advances, which have of late years been polyanthus of unnumbered dyes, nor in the tulip made in the science of chemistry, readily explain in race would beauty play her idle freaks. To the in- what manner water serves as an alimentary princiQuence of light, vegetables are indebted not only ple of vegetables. We now know that the above for their colour, but also for their odour, their taste, fluid, formerly ranked with air among the four eletheir combustibility. their maturity, and the resi-ments of nature, is compounded of oxygen and hy LAVOISIER. drogen; or, in other words, that water is an oxide of hydrogen. This compound body, then, suffers a decomposition, when absorbed by the vegetable; the hydrogen becoming a principle of the vegetable, while the oxygen is partly thrown off by the vital forces, and partly applied to the production of vegetable acids. Hence the analysis of a plant yields hydrogen as the most abundant element of its products. Mucilage, oils and resins are principally composed of hydrogen; and in plants subsisting on water and air, there is no source from which it can be drawn except fron the decomposition of the water. The utility of the soil, then, consists principally We will now point our attention to those circum-in affording a support to the growing vegetable, and stances which are to be considered as the food of in conveying water to it more or less pure. "Elle plants. This may appear a sort of retrograde, or ne l'est pas plus" says Chaptal, "que le placenta, qui unnatural movement, the progress of a plant being par luimême ne fournit rien a la vie de l'Enfant, mais already traced to its fructification. The fact, how-qui prépare et dispose le sang de la mére á devenir "L'organisation, le sentiment, le mouvement spontane, la vie n'existent qu'a la surface de la terre and dans les lieux exposès à la lumière On diroit que la Fable du Flambeau de Promethee toit l'expression d'une verite philosophique qui n'avoit point echappe aux anciens. Sans la lumière la nature etoit sans vie, elle étoit morte and inanimee: un Dieu bienfaisant, That oxygen gas is emitted by the leaves of en apportant la Lumière, a repandu sur la surface de plants, we also derive from the celebrated Priest-la Terre l'organisation, le sentiment and la pensée." ley; but for the explanation of this fact, we are in debted to Sennebier. Finding that no air is emitted by leaves plunged into water previously boiled; that water impregnated with the greatest quantity of carbonic acid gas, afforded most air; that no oxygen is yielded by water totally destitute of this gas; that the quantity of oxygen emitted is proportional to that of the carbonic acid gas contained in the water; that the property of yielding oxygen with leaves, is gradually lost by water impregnated with carbonic acid gas; that whenever this happens, all the carbonic acid gas has disappeared; and finding also that the property of emitting oxygen was restored by adding more carbonic acid gas-Sennebier, from this concatenation of facts, has drawn the legitimate conclusion, that the oxygen gas emitted by the leaves of plants, depends upon the presence Shakspeare's "As you Like it." "The glories of the American Flora," says Pinkertor, in terms equally elegant and correct, "the glories of the American Flora are principally confined to Virgini and the southern states. It is here that the unfadin; verdure of the wide savannas, the solemn magnificence of the primeval forests, and the wild exuberance of the steaming swamps, offer to the astonished admiraion of the botanist, every thing that by colour, by frgrance, and by form, can delight the senses and fix the attention." See Pinkerton's Geography. une nairriture convenable; elle ne l'est pas plus que les divers reservoirs que la nature a placès dans le corps de l'homme pour conserver les diverses humeurs et les livrer au besoin." The earthy and saline particles, occasionally found in the analysis of plants, seem not to be peculiar to their composition; as there are plants in which we scarcely discover any, and others again which contain a great quantity of them. By the analysis of the Byssus Periza, and several other cryptogamic plants, particularly of the genus of Fangi, we find no earth in their mixture; while in Hypnum Crista Castrensis, Neckera Dentroides and Chara Vulgaris, we find it in great proportion.*Earths can obtain their admission into plants only in a state of solution, or at least suspended in water in a state of division as minute as if they had really For the fixed alkalies afforded by plants, we find it difficult to account, as their constituent principles have hitherto eluded the grasp of analysis. Kirwan regards them as formed by the elaboration of the vegetable powers. been dissolved. From the experiments of Ruckert, in Crell's Annals for 1788, it appears that plants vegetate much faster when growing in earth moistened daily with water impregnated with carbonic acid gas; and the observation of Sennebier, that plants thus watered with carbonic acid, transpire a much greater quantity of oxygen, places it beyond the reach of doubt that the carbonic acid undergoes a decomposition, though so difficult to be accomplished by art, and that it is from this source that the carbonaceous matter of the vegetable is derived. Hence we are justified in regarding as an alimentary principle of vegetables, the carbonic acid dispersed in the atmosphere, and from its superior gravity descending to the earth. It is certainly the only clear fountain from which can be drawn the carbon of vegetables growing in air and water. Dr. Percival, of Manchester, and Ruckert, have established by their experiments, that carbonic acid gas imbibed by the roots of plants promotes their vegetation. Kirwan thinks that, by acting as a stimulant, it assists the decomposition of water. The carbonic acid of the atmosphere may, then, be absorbed not only by the leaves of vegetables, but also be conveyed with the water absorbed by their roots. We have thus seen that water, more or less impregnated with matter from the soil, is taken up by the roots; that carbonic acid is received immediately from the atmosphere, or from the docomposition of the matters contained in the earth; that from the commixture of these substances is formed the sap. the nature of which is changed by the elaboration of the vegetable. Vegetables, then, as subservient to the formation bles, are mucilage, or gum, fecula, saccharine mat-projected another shortened and pointed limb. The So it is with MAN, that proud lord of the creation, and with those monuments by him erected to stretch beyond the narrow span of his own existence. Plants, in their decline and fall, sink to vegetable dust; but their seeds, bearing in them a principle of life, are evolved in the general wreck by the very principles which produce it; and thus, as one gene ration flits away, another springs into view. "The cloud-capt towers, the gorgeous palaces, SHAKSPEARE. PRESERVATION OF CORN. TO FARMERS.-A writer in one of the Dover pa The ancient Greek plough, described by Hesiod, consisted of three parts-a long block sharpened at the point; a draught pole attached obliquely to the upper part of the block, and extending to the yoke; and a plough tail to direct the implement, fastened in like manner, and extending back. A plough of a similar construction is now used in Sicily. The plough of the modern Greeks has a crooked share shaped like the claw of an anchor; it is only a constrong. The most ancient plough used by the Rotinuation of the sloping handle, which is large and of their chemical products, perform the functions pers states, that previous to planting his corn last mans, was of the simplest form. In the days of Viryear, he soaked it as he supposed in a solution of tion. The first is carried on by vessels arising from/nitre, but found when most of the seed was in the and efficient. They had ploughs with and without of absorption, perspiration, respiration and secregil this implemen had become more complicated the root, bark and leaves. The second is princi sults. He planted four acres; the seed for two of without wheels; with broad and narrow pointed ground, that through mistake he had use glauber mould-boards; with and without coulters; with and pally performed by the leaves. The third is exem-which was in its natural state; that for the other shares. The beam was fastened to the yoke, like plified in the emission of oxygen and absorption of two was soaked in water in which was dissolved one carbonic acid by the leaves when exposed to the pound of the salts. Discovering his mistake, he of lands in beds or ridges, as we on; but the cattle alour cart-pole. The Romans did not plough their light. The function of secretion, by which the vegetable products are chiefly formed, is supposed to his crop. The result was, that the seed that was monly used had no mould-board, and this may be course felt a degree of anxiety as to the success of ways return in the same furrow. The plough combe conducted in the utricles, already described. thus soaked came up three or four days before the remarked of the ploughs of most amient, and some According to Dr. Darwin, in the leaves of plants other, and was not injured by birds or worms, while modern nations. a circulation is performed. Through the centre of one half of the hills on the other two acres required the leaf, from the base to the apex, we know that a to be planted a second time. He then made sevelarge vessel shapes its course, which deals out ral experiments. Some corn which had been thus branches that extend to very minute ramifications, leached was thrown to a hen, which made sevenfreely anastomozing with each other. Dr. Darwin teen unsuccessful efforts to swallow it. When mixingeniously supposes this large vessel to convey sap, ed with other corn and exposed where the worms, and that it discharges the function of a pulmonary squirrels, and birds could have access to it, he artery, by distributing the fluid over an extensive found that it remained untouched, while that surface exposed to the atmosphere. From its ex-which had not been thus prepared, was invariably tremities, the fluid, changed in its composition, redestroyed. turns by vessels running along the inferior surface, and these, conjoining at the foot-stalk, pass perhaps to the utricles, or to other parts of the plant. The products, or proximate principles of vegeta* See Von Uslar on Plants-Kirwan on Manures. According to Dr. Hope, the atmosphere is composed of 22 parts of oxygen, 77 parts of azote or nitrogen, and one part of carbonic acid. Chemists are at this moment disputing whether the carbonic acid forms an essential ingredient, or whether it be adventitious. Doctor Hope adopts the latter opinion. THE PLOUGH. HORTICULTURE. (From the Philadelphia Album.) ON THE CULTIVATION OF SILK. By Doctor John T. Sharpless, of Philadelphia. (Concluded from p. 117.) Mr. E. C. Genet, of Albany, in a letter to me on the subject, last summer, considers the drill from the seed or cutting decidedly the best. They must This instrument has held the first place among be kept under constant irrigation, and if light, black, the implements of agriculture in all ages. Noah cul- sandy mould, called heath soil, could be procured tivated the vine and made wine immediately ater for a manure, the production of the best leaves tivated on the banks of the Nile, in Egypt. The about a foot and a half in length, and put down late the flood, but it is supposed that grain was first all-would be almost inevitable. The slips should be invention of the plough must have been nearly to- in the fall after the ground has been deeply dug and eval with the raising of grain. "The first plougi," manured. says John, in his Biblical Archæology, "was 10- The tree is sometimes allowed to grow to its full thing more than the stout limb of a tree, from whch | size of 15 or 20 feet. Most of the worms ever rais ed near this city, depended on such for nourishment, to be manufactured; but when a strong thread is Sometimes it is required to discharge colours and and they appeared to thrive well. No doubt, there- required, two threads thus twisted are placed toge- introduce new ones. The principle consists in refore, can exist as to the quality of the food; but the ther and turned in the contrary direction, producing moving the mordant, and the colour will naturally object to be attained is to procure the largest quan- a thread like a rope. This double or even treble escape. If this has been an alkali, as tartar or tity possible, from a given portion of ground. To thread is principally used as the warp of stuffs, alum, a weak solution of an acid, as oil of vitriol, institute, therefore, a comparison, is the best me- whilst stocking silk is only yarn. will neutralize it; but if a solution of tin has been thod to decide on each system. Mr. Genet says, It is now boiled in soft water, with a quantity of used, an alkali is required. It may then be bleach"one twentieth of an acre, planted with bushes not fine soap, say twenty or thirty pounds, according to ed. If, however, the colour cannot be removed, it more than three years old, will supply 100,000 the lightness of the colour intended for the dye, to may be changed into a darker or mixed tint, of worms, and will produce 30 pounds of silk; and if a the one hundred pounds of silk. The gum is thus which the original colour is a constituent. whole acre be so planted, the product will be 600 dissolved; the fibres are almost incorporated with The silk is now prepared for the loom, which propounds, equal to 2,000,000 of animals. Forty thou- each other; the thread becomes much larger, softer cess is varied to suit the article. It is first warped, sand worms will consume one thousand pounds of and more pliable, whilst it loses nearly one-fourth or the chain is laid parallel, and equally tight, and leaves, easily supplied by fifty grown, or two hun-of its weight. The silk is then beetled, or washed then placed in the loom, after which the mechanical dred small trees, of two or three years old, and will and beaten, to remove all the soap, as that sub-operation is like that in cotton or wool. One thing produce twelve pounds of drawn silk." Mr. Genet stance, however small the quantity, prevents the is necessary to be known, that the dressing comcontinues, "from my experience, mulberry trees, effect of the dyeing material. If the silk is to re-monly given to the other substances always injures trimmed down every year near to the ground, will main white, this operation is repeated three times, silk. After weaving, the pressing and other prepayield more than if placed in order to grow to their but with a less quantity of soap. It is then exposed rations must vary, according to the fabric. full size. The most correct calculation is, that fifty to the fumes of sulphur, and subjected to other protrees of twenty-five or thirty years old will support cesses, according to the purity of the colour intend40,000 worms, and will yield but 8 or 10 pounds of ed. As the use of the soap has in some instances insilk; whilst 100 trees, which occupy one acre of jured the lustre of the thread, it has been proposed ground, can produce but 20 pounds." Mr. Fitch to use a weak solution of an alkali, as soda; but it says, "one acre of full grown trees, set a rod and a does not dissolve the gum, which is necessary to half apart, will produce forty pounds of spun silk." enable the dye to take effect. The necessity of engrafting also becomes an interesting question. Count Dondola considers the wild or unengrafted tree as bearing the most nutritious food; but he has not tested the matter completely, as almost all the trees in his country are engrafted; the artificial branches are also much shorter lived than the natural. Some kinds of silks are dyed in the thread, and others in the stuff, but the same principle holds good both in the practice and in the theory. The most rational explanation of the application of dyes, is, that an actual chemical connexion takes place between the colouring matter and the fibre, by the intervention of a third substance, called a mordant. These are salts of various kinds, which are different according to the colour. The same writer says, the older a natural tree Fourteen and a half pounds of wild leaves, weigh- As it would be useless to enter minutely into the From all that has been said, it would appear that the bushes planted in rows, and kept to the height of five or six feet, grafted or unengrafted, are the best calculated to yield the largest quantity of the best silk. For further information on the mulberry, see La Maison Rustique; Technical Repository; Millar's Gardener's Dictionary; Horticultural Transactions; Loudon's Gardening; Manuel du Jardinier, &c. &c. To proceed with the manufacture of silk. After the thread has been reeled and dried, it is throwsted or twisted. The object of this operation is, to more completely unite the different fibres of which it is composed; being flat, or nearly so, on the reel. Many very complicated machines have been invented for this purpose; but as it is impossible in a mere essay to go into a detail of every manipulation on this or any other section of the subject, I shall confine myself to an outline. It is first wound from the skein on to bobbins or spools; then by an arrangement somewhat similar to the spool of a spinning wheel with a flyer, which is rapidly turned by machinery, it is again unwound into a skein, receiving a twist to the right or left hand, and of greater or lesser tightness, according to the fabric intended. It is sometimes left with this twist alone, To produce the variety of red tints, cochineal, Brazil wood, madder, &c. are employed; but the first is most generally used, as giving the finest and most durable colour. The different shades are produced by adding galls, copperas, &c. to the dyeing mixtures. For blue, indigo is preferred; though logwood and Prussian blue are used. With indigo, no mordant is required. The blue vat, which is a mixture of indigo, potass, madder, bran, &c. being sufficient. For purple, or violet, a red is added to the blue ground. For green, a yellow is added to the blue ground, or substances to produce both tints are used together, as weld and logwood; and for yellow alone, weld, turmeric, fustic, &c. For black, alum is never employed. The principle consists in adding a quantity of galls or sumac, to solutions of iron and its compounds, as copperas, which act on each other as in the production of ink. A black may be produced by boiling the silk in a decoction of walnut rinds, then passing it through a strong dye of logwood; and lastly, if a good black be desired, it is dipped into a mixture of gall, copperas, and gum Arabic. The gum is afterwards washed out, and the air perfects the colour.* *I before mentioned that boiling diminished the weight of silk by depriving it of its gum, but dyeing increases its weight in a great degree, in black, particularly when the galls are used; from four to six ounces are added to the pound of silk. INTERNAL IMPROVEMENT. (From the National Intelligencer.) ABSTRACT OF A PLAN OF A RAIL-ROAD, Peculiarly adapted to facilitate the operations of the mail, with an estimate of the cost of one between the City of Washington and the City of New Orleans, in a letter from ROBERT MILLS, Engineer and Architect, to the Post Master General of the United States. DEAR SIR, Columbia, S. C. December 16, 1826. Very respectfully, dear sir, I salute you, The Postmaster General of the U. States: SIR-The subject to which I would now take the liberty of calling your attention, is one in which the department over which you preside is particularly interested, and, from this circumstance, every part of the union-I allude to the operations of the Mail, in its safe and rapid transmission from place to place. From the nature of my professional pursuits, I have had frequent opportunities of noticing the modus operandi in transmitting the mail, the delays to which it is subject, and its unavoidable exposure to the hand of the depredator. The importance of rectifying these defects has often been acknowledged, and various plans suggested to effect it; but, as they all required, as a prerequisite, the construction of good firm roads, insuperable difficulties, on the ground of expense, intervened to cause them to be laid aside. Besides, were even such roads constructed, they would still be defective, as little increase of speed, beyond what is now obtained, would result from them. But the establishment of a permanent road to New Orleans, from the City of Washington, will probably never be realized, at least in our day, the expense of such a road being beyond any available means in the hands of the Government; the inquiry therefore is, what practicable plan of road can be devised, suitable for the transportation of the Mail, and which will ensure safety, with the degree of despatch necessary for the occasion? The safe and rapid conveyance of the public mail is of the utmost moment to the public interests; for so small a matter (abstractly considered) there is deserts. FIRST.-THE PLAN. Many circumstances combine to point out the expediency of forming this rail-way of wood. The tion from decay, its economy is evident, and it is plan of its construction is favourable to its preservaeasily kept in repair at a very trifling expense. We constructed of wood. will take it for granted, that our rail-way would be SECOND. THE EXPENSE. 400 00 200 00 The timber necessary for the rails, supports, and braces, will cost on an average per mile, about $400 00 Preparing and putting up the same, Opening and making up the track road, Contingent expenses for tunnels, bridges, &c.300 00 Cost of one mile of this road, not a more powerful agent; though its operations form of rail-way which adapts itself so well (both 4th. The time now employed in conveying the mail are silent and unobtrusive, its influences are widely on account of its economy and capacity to admit of from Washington to New Orleans, compared with felt, and tend most effectually to secure the liberty great speed in travelling) for the transportation of the time it would take to transport it on the railand happiness of the country, by becoming the me- the Mail. road. And 5th, The revenue which this road could dium of intelligence to the whole community. This rail-way differs entirely from those common- be made to yield. Viewed in this interesting light, no attention that ly used. It consists of a single in place of a double can be bestowed upon it, or expense incurred to im- rail, raised at least 3 feet above the ground, and prove its powers of locomotion, (if we may so speak,) supported by pillars or posts placed at an average ought to be considered too great, or beyond its distance of about 9 feet, if of iron, and 15 feet if of wood. The carriage (supported by two wheels,) Rail-roads are unquestionably the most efficient, consists of two receptacles, or boxes, suspended economical, and practicable mode of accomplish- on each side of the rail by an iron or wood frame; ing the object of our inquiry. Carriages moving the wheels (about 30 inches in diameter) are placed upon a road of this kind, bear the nearest analogy in the same line on the rail, the face of the rims to a body impelled on the smooth surface of ice, made concave and fitted to the convex surface of where the velocity given by a small power is im- the rail; the centre of gravity of the carriage, whemense; what the rails want in smoothness being ther loaded or empty, is so far below the upper compensated for by the use of the wheels. edge of the rail, that the receptacles hang in equiThe rapid increase of these roads in England, librium, (though provision is made to obviate any leads us to anticipate their early adoption into the difficulty that may arise on this head) and will bear United States, and truly there is no country in the a considerable inequality of load without any incon world where their introduction would be attended venience, even two to one, owing to the little change with such incalculable and increasing advantages of fulcrum, from the breadth of the rail, which is as in this. Such is the enterprising spirit of our about four inches. citizens, that it would create little surprise, if, in This rail-way is subject to less lateral friction less than ten years, we should witness roads of this than even the edge rails, and, being raised higher description traversing our hills, climbing our moun- above the ground, is not so liable to be covered with tains, and bringing in the wealth of the west, to dust, or any extraneous matter likely to affect the reward the industry of those cities, on the eastern motion of the carriages. Its advantages are great side of the mountains, which shall have effected in another way: for, where the surface of the counthese splendid works. Happy is it for our country try undulates considerably, a railway of this kind that this system of improvement has been so early may be made without cutting to level the surface, substituted for that of canals. What an honour will except so far as is necessary to make a path that a redound to that city which shall first accomplish the horse can travel in; (provided horse-power is to be great work of throwing a chain of connection like used.) When horses are employed, a track rope is this, between the east and west! Every city on required, which enables them to draw without mathis side of the Allegany mountains can now by this terial alteration of the angle of draught, while the means partake of the commerce of the western weight of the rope serves as a spring to regulate the world; and, truly, the trade of this region will prove variable exertions of the horse. more than enough to satisfy all. The annexed drawing exhibits a view of this roadLet us now proceed to examine that peculiar way with its carriage in operation. If the top of the wooden rail is cased with $1300 00 900 00 Cost of one mile of road with iron edge, $2,200 00 THIRD.-COST OF TRANSPORTATION. The cost of transporting a daily mail from the To transport a daily mail between these Difference, $96,000 00 0 00 $96,000 00 We will now shew in what manner the mail may be carried free of expense to the Government. The annual expenses of a stage coach and team of four horses, amount to $800. The work performed by this team (the space travelled over) never exceeds 25 miles a day. It, therefore, would require at least thirty horses to supply 100 miles of road where a daily mail is carried. Now, on the rail-way, for the same distance, the number of horses need never exceed four, (nay, we have already shewn that horses might be dispensed with altogether on this road, and the driver be constituted the moving power of the carriage.) The small force necessary to propel a carriage on A road of this kind would be more free from inthis rail-way, would enable a man alone to do it, and terruptions than any other, and a velocity sufficient with great ease to himself, as he might work the for any useful purpose, may be obtained at a small wheels in a manner similar to one rowing a boat: expense of power. As to the circumstance of the (the power of a man being as 1 to 6 of that of a single rail dividing the carriage into two parts, that horse, he could move near 4000 pounds.) It has would most likely be esteemed a recommendation. been remarked by an eminent engineer in England, Several of these rail-ways are now in successful But we will take it for granted that horse power (Mr. Tredgold) that this single rail-way will be operation in England. Their economy of construc- is used to propel the carriages; the expense, then, found, by far, superior to any other for the convey- tion, and capacity for transporting heavy burthens, that mail contractors would incur, in a distance, say ance of the mails, and those light carriages of which are such, that little doubt exists that they will of 100 miles of this road, will not exceed four dolspeed is the principle object; because it is evident come into extensive use as roads of business, also. lars; now one passenger, at only four cents per mile, that a road for such carriages must be raised so as The calculations made in relation to the effect pro- would pay this sum. But the travelling on a road to remove the possibility of overrunning people, or duced on these roads, compared with that on double of this nature, will, in time, be very considerable: dashing against other vehicles. Carriages running rail-ways, go to prove that the single rail way will allowing now, however, only 10 or 12 passengers to smoothly and rapidly with a small moving power, carry most weight, in proportion to the number of be the average number daily, (which is certainly a cannot be checked suddenly, and they admit of no wheels employed. small average,) the profits of the contractor for 100 miles of road, would then amount to the enormous change of direction; but were a rail-way elevated We will now proceed to consider brieflyeight or ten feet above the common road, these ac- 1st. The most economical mode of constructing sum of 16,000 dollars annually. The presumption cidents could not take place, except through neg- this road. 2d. The expense of its execution per is rather that the contractor will be required to pay lect; the passengers would not be raised much mile, and cost of one upon this plan from Wash-a toll, in proportion to the number of passengers he higher than the top of a common coach, and in a ington to New Orleans. 3d. The expense now in- carries on this road, for the privilege of using it; suspended carriage, which could not possibly over-curred in transporting the mail, compared with (this we shall notice hereafter.) When horses are turn. what it would be subject to on the plan proposed. [used on a rail-road, and great speed is required, it is important to be well acquainted with the natural powers of these animals, under different circumstances of velocity; let us, therefore, take a brief review, of this part of the subject. The average power of a horse unloaded is equal to 250 pounds; the maximum of useful effect is, however, only half of this, or 125 pounds. A good horse unloaded, cannot, without injury to him:self, travel more than 6 hours a day, at the rate of 6 miles an hour; consequently, 3 miles per hour must be the velocity corresponding to the maximum of effect, when the time of labour is 6 hours. In the ratio of increase of speed, must, then, always be the reduction of time of working—if the hours are lengthened, the velocity must be reduced in proportion. The annexed table exhibits the ratio of this graduation. When the duration of labour is The maximum veloci h. 7 h. 8 h. 10h. 1 h. h. 3 h. 4 h. 5 h. ty unloaded in miles 14.7 10.4 8.5 7.8 6.6 6. 5.5 5.21 4.6 per hour, is But half the above must be the maximum velo Richmond 57 miles. the actual labour performed by such horse average | From the City of Washington to Fredericksburg at FIFTH.-REVENUE. Total amount of Revenue $96,000 $60,000 $156,000 Sixty thousand dollars must be considered a mocity. It is, also, important, in the use of horse pow-derate charge of toll on this road for passengers, as er, to be able to determine the proportion of work it is the aggregate of a little more than of a cent that should be done when the time of labour is shortened. 66 cost now is of transporting the mail from Washington road confined to the undulations of the country must We have shown, under the 3d head, what the it admits of overcoming many difficulties which a From the peculiar construction of this rail-way to New Orleans. This expense, as it will be saved be subject to. It is capable of rising and falling to to the Government, properly belongs to the head of suit any local circumstances, whether originating Revenue to the road: we shall therefore assume it as out of the intersection of a town, city, public bighsuch, and carry it to this account in full way, valley, hill, or river. Where the carriage deThe revenue arising from the transit of scends to the ground, (for instance in a town,) it is passengers beyond the profits allowed provided with truck wheels, to enable it to be rolled to mail contractors, may be estimated along the pavement, connecting the two sections of the rail-way; where a public road crosses, or the point of change in the direction of the travelling occurs, the same plan can be pursued, or (with reference to the first,) the rail may be elevated high enough to admit of carriages passing under it. But it is not requisite here to enter into any deon each person per mile, and supposes but ten pas-tails of this nature-suitableness of this plan of road, sengers per day. If we allow an average of twelve to the object in view, is the fact most important The best division of the labour of horses, for heavy passengers each way, and charge one cent per first to establish. This, I hope, (after what has carriages is as follows: To divide the road into mile on each, or ten dollars through, then (twelve been advanced,) is satisfactorily proved. stages of 9 miles each, when the day's work is 6 each way,) twenty-four passengers, at ten dollars, With sentiments of the highest respect, I have hours, and to work the horses 3 hours, with an in-equal $240, by 365 days, (the year) equal $87,600 the honour, sir, to salute you. terval of 6 hours between that and the next 3 hours' per annum. One cent per mile is certainly a very ROBERT MILLS, labour. When the duration of labour is 6 hours, it low toll, as one cent more will pay the coach proEngineer and Architect. has been shewn that the maximum velocity will be prietor his profit; so that the stage fare of each pas8 miles per hour. Whatever greater degree of ve- senger from Washington to New Orleans, would locity than this is obtained, must be at an additional not amount to more than twenty dollars, (1-5 of what expense, (which is always inversely as the product of it is now.) the velocity by the duration of the labour.) As soon, therefore, as the speed exceeds 44 miles per hour, there is a decided advantage in shortening the duration of labour, in preference to reducing the quantity of draught. Stage proprietors act upon this principle. They find it more profitable some times to double the quantity of labour here assigned to a horse, though they are aware that, in so doing, they will destroy the animal in three or four years. But in a large business, stage proprietors do not hearising from this source, the political and commercial sitate sacrificing one third of their stock of horses every year on this account; for the difference between the interest that will return the excess of capital expended in the purchase of the first horses, and the annual expense of keeping a great number, is too great for them to hesitate to make the sacrifice. This is a melancholy truth; may we not hope, however, observes a writer on the subject, that railroads will, in some degree, lessen the evil and diminish the quantity of animal torture? FOURTH.-TIME. From this exhibit, it is very evident that ample means will be provided from the tolls, &c. of this road, not only to pay the interest on the largest capital required to execute the work, but every contingent expense for repairs, superintendents, &c. besides reserving a sinking fund, either to extinguish the original debt, or provide for the construction of another road alongside, and for lateral branch roads. But, independent of all pecuniary advantages benefits that would be derived to the whole country, from the rapid, safe, and certain transportation of the mail, are incalculable. I need not occupy time in reviewing these, as they will be evident, sir, to your mind at a glance. Before closing this rapid sketch of our subject, we will, for the purpose of shewing the practical operations of this road, locate its line, and give the time of arrival at, and departure of the mails from, particular points. LOCATION OF THE ROAD. Columbia, S. C. Dec. 16th, 1826. LADIES' DEPARTMENT. (From the Literary Gazette.) They grew together, Two lovely berries moulded on one stem; I SAW them when their bud of life Had burst above their natal bower,- What were they then? Two twinkling stars- The time at present occupied in transporting the Regarding this road as a national object, policy The actual rate at which some of the quick coach es travel, is ten miles an hour. The stages to the North, where there is much competition, average nine miles an hour. A coach, with its load of bag gage and passengers, weighs about 3000 lbs. the average day's work of four coach horses is 13 tons, drawn one mile, or 3 3-8 tons per horse, drawn one mile-which is about equal to the extreme power of a horse at that speed upon a good level turnpike road. From this should be deducted the loss of ef fect in ascending hills, heavy roads, &c. which makes The total length of this road is estimated at 1,050 miles; the present distance (which is very circuitous in many places) is laid down at 1,143 miles, namely: With careless brows and laughing eyes; They flash upon my soul again Such Fancy's dreams--but never more May Fancy with such dreams be fed; Before their leaves had time to spread,- |