We have just given some examples of cases, in which it is wished to build an engine for a particalar end. The contrary case naturally presents itself afterwards. The question is, what effect may be expected from a given engine, that is to say, from an engine already constructed, and the dimensions of which can be measured. In order to give here a practical and extensive application of the formula which resolve this question, we shall calculate, after the formula, § 1, a table of the velocity which engines, similar to those of Liverpool, viz. with 11 and 12 in. cylinders, will acquire with given loads. By that means, the experiments, which we are going to make on the Liverpool engines, will serve to verify, by facts, the accuracy of the formulæ, which we have deduced from principle. As we think that this table, like the preceding ones, may be useful to practical men, in showing them the results, without obliging them to make the calculation, we shall extend it further to engines of different powers, such as are most in use on railways. It will be remarked, that this table, giving the velocity corresponding to known loads, naturally furnishes also the loads of the engine, when, on the contrary, the velocity is given a priori. In like manner, as we have necessarily been obliged to confine ourselves, in each column, to the limit of load which the engine is capable of drawing at the pressure indicated, after the formula in § 4; so it follows that the same table gives equally the maximum loads for each pressure, as well as their correspond. ing velocity. In the last column, the state of the regulator is indicated as follows: when it is entirely open, we write 1; when only half open,; etc. This relates to the following tables, as well as to this one: 1 ▲ PRACTICAL TABLE OF THE VELOCITY OF THE ENGINES WITH GIVEN LOADS, AND OF THE LOAD CORRESPONDING TO A GIVEN VELOCITY. We remark here, as we have said above,||vantage we observe here in favor of a that the whole influence of the pressure greater pressure is only owing to the fire bears upon the limit of the load, but that its being in that case naturally more intense effect is almost insensible on the velocity. a circumstance from which results, not that This result agrees with the principle; for there is more water evaparated, but the if the pressure required on the piston to same quantity, notwithstanding a higher move the load, be, for instance, 46 lbs. per pressure. square inch, is it not true that, provided the These tables show the effect that may steam be abundantly furnished at that pres-be expected from an engine of given prosure, by the heating surface, it is of little portions, in regard either to the speed or to consequence whether it be at first col- the load; but it is understood that the effect lected in the boiler at a pressure of 75 lbs. can only be produced if the engine is put or 65 lbs. or at any other degree? Finally, in a situation to apply all its power. at the moment of acting, it must any how If, for instance, instead of the fire being be transformed into steam at 46 lbs. pres-sufficiently animated, it is left to languish, sure, and the speed will depend solely on the quantity of water evaporated per minute the quantity of steam at 46 lbs. that the will be diminished, and at the same time boiler will have furnished. The small ad- he effect of the engine. If the engine, instead of being in good order, loses its steam, either by leaks in the boiler, or round the piston, or by the stuffing boxes, or elsewhere, it is clear that the effect must also be proportionately diminished. If, by diminishing the opening of the regulator, we let only a portion of the generated steam penetrate into the cylinders, the boiler continuing at first to furnish the same quantity, more steam will necessarily be lost by the valves without acting on the pistons. Afterwards, as soon as the dimi nution of the steam thrown into the chimney has moderated the fire, there will be less steam generated, and that will consequently regulate the velocity. This is the case of all small loads drawn by the engines. The speed is never suffered to augment sufficiently to risk an accident by too rapida motion of the piston or other parts of the mechanism. When the engine-men perceive that the train would run too fast, they diminish the aperture of the regulator, and make a moderate fire, in order to maintain a reasonable speed. In all the experiments we shall have occasion to relate below, we shall only once see, as we have already observed, the speed rise to 35 miles an hour, which is the greatest speed to which the engines have been hitherto submitted, excepting for a very short instant. In the above tables, the limits of load of the engines, with the indicative pressure, are fixed by the necessity of the resistance on the piston not being greater than the force that must move it, as we have already said. With that maximum load, we see that an eleven-inch cylinder engine, working at 60 lbs. effective pressure, will still maintain a velocity of 13 miles; and a twelve-inch cylinder engine, with an effective pressure of 55 lbs., will still maintain a speed of 12 miles an hour. These velocities are those which will take place if the engine works in its right state; that is to say, if the valve is fixed for a pressure of 60 lbs. or 55 lbs. But if it should happen that the valve be only regulated for a pressure of 50 lbs., and the pressure of 60 lbs. or 55 lbs. be produced by an extraordinary rising of the valve and by dint of losing steam, that is to say, only because the steam above 50 lbs. cannot escape as quickly as it is generated, then it is clear that although the evaporating power of the boiler remains the same, the effective part of that power will be considerably reduced, and, consequently, also the velocity. It is for that reason that, in the experiments, we shall see the speed go sometimes down to two or three miles an hour. But the state of the valve must then be observed. The elevated pressure will be seen to be produced only by an enormous loss of steam, and it will be easy, by the rising of the valve, to account for the diminution of speed. In the cases of maximum load, it is evident that the steam will be spent by the cylinder, at the same pressure at which it has been generated in the boiler, and that the peed of the piston will be equal to the uickness with which the steam is generatThis fact has been proved in a genral manner in §5 of the present article, d. It may be verified here by calculating the|| Those cases of limit roads are those of which we have made use to determine the friction of the loaded engine, and we see here the principle justified, of which we then made use, viz. that in case the speed of these engines is under 12 miles an hour, the pressure in the cylinder is the same as in the boiler. We have one observation more to make, which is, that in the engines there always exists a small loss, which we have not taken into account in our calculation; that is to say, the loss of the steam which, at each stroke of the piston, fills the passages that lead from the slides to the cylinders. It would be easy to take it into account, by the measures taken on each engine, of the diameter and length of these passages; but this loss is very insignificant, and would only complicate the calculation without any advantage. ARTICLE VII. CONFIRMATION OF THE ABOVE FORMULE § 1. Experiments on the Velocity and As a verification of the formulæ we have laid down, and with a view to enable our readers to rest their calculations on material facts, we shall give here a series of experiments undertaken by us, in order to ascertain the speed with which the engines draw different loads at different degrees of pressure of the steam, in their daily and regular work. From these different inclinations, we see || exactly in tons, cwts., quarters, and pounds. that the same train presents various degrees The tender cartwrights were not weighed, of resistance, according to the part of the but they are reckoned at their average road travelled over, because the gravity of weight of 5 t. when a fresh supply of water the total mass in motion becomes an allevi- is taken in on the road, and 5 t. only in the ation in the descents, and an additional ob- contrary case. stacle in the rising ground. The result is, that a train of 100 t., offers on a dead level a resistance of 800 lbs. ; besides the friction of the engine; and that the same train, if it is, for instance, drawn by an engine weighing 10 t., will, on arriving at an ascent of, offer a resistance of 3,366 lbs., which upon a dead level would be equal to the resistance of a train of 421 t. In fact, if we observe that a ton weighs 2,240 lbs., we shall find for the resistance: 100 × 8 lbs. 100 × 2,240 lbs. 10 x 2,240 lbs. 96 friction. 2,333 lbs. resistance We have marked the state of the weather, because it is a known fact that with the wind a-head, and still more with a sidewind that presses the flange of the wheels against the rails, the resistance of the train is augmented. Finally we have also mentioned the temperature of the water in the tender, in order that the reader may judge of the influence of that circumstance; and we have given the date of each of the experiments as a means of verification. (To be Continued.) 800 lbs. ; resistance I witnessed at the capitol with great owing to the pleasure on Monday last, Mr. Smith Cram's (of the city of New-York) inven. tion for overcoming an elevation in Rail. road transportation of 440 feet to the mile. It was performed with expedition by a single stroke perpendicular engine, which in point of power suffers much in comparison with a double stroke Locomotive Engine. owing to the train, on a at 6. engine. 3,366 lbs. total resist- His plan, as exhibted, puts at rest all 233 lbs. similar re- doubt as to the practicability of ascending and descending hills from 450 to 600 sistance owfeet to the mile, with certainty and secu. ing to the gravity of the rity. As to the certainty of overcoming elevation and inclination, the cog-wheels and ratchets as arranged satisfactorily show. As to the security, it is to be found in the introduction of his hydrostatic cylinder attached to the car which is designed to check the train of cars in ascending should any accident befal the engine, and to regulate their velocity in descending, or check them altogether. The accuracy of the principle in both cases is perfectly clear, and promises to be of incalculable value in the present age of improvement; and I doubt not it will be generally adopted upon the score of economy as to time and money; but above all in the preservation of human life, which his plan so effectually guarantees, in comparison with the present mode of overcoming a trifling elevation by sta tionary power, committing our lives to the hazard of a single rope. load of 3366 = 8 421 t. on a level. That is the manner in which we have calculated the real load of the engine on the different slopes it had to pass over during its journey. These experiments were made on the The following column marks the presLiverpool and Manchester Railway, the sure in the boiler, expressed first by the section of which, according to a levelling state of the balance, and then by its equivamade in the month of August 1833, by Mr. lent on the mercurial gauge. Thus, when Dixon, resident engineer, is as follows. the balance, fixed at 57, rose by the blowWe only give the part travelled over by the ing to 58, we have written 57-58; and as locomotive engines; there are, besides, for the ATLAS, for instance, that state of under the city of Liverpool, three tunnels the balance corresponds with an effective worked by separate stationary steam en-pressure by the mercurial gauge of 61 lbs., gines. we have written 57-5861 lb. The railway, on leaving the station We have also noted the state of the reguat Liverpool, until it terminates at Man-lator; but we must add, that the handle of chester, passes over the following distances the regulator in these engines not turning and slopes: Miles. on a graduated circle, as it would be better TO CONTRACTORS. PROPOSALS will be received at the Office of the Eastern Railroad Company, Boston, between the The line of this road is along a favorable country, The speeds have been carefully taken 28th and 30th inst., for the grading and masonry of down, by inscribing in minutes and quart-said Road from East Bosion to Newburyport, a disers of minute the time when the engine tance of 33 miles passed before every quarter-mile stone of the road. These stones are numbered all along the way. At the same moment we noted the pressure in the boiler as marked on the valve balance. The weight of the wagons was taken passing through Lynn, Salem, Beverly, and Ipswich, which places will afford contractors every facility for ready, and may be seen at the Office, after the 224 obtaining provisions, &c. Plans and Profiles will be instant. Satisfactory recommendations must accompany the proposals of those who are unknown to the Engineer. 22-130j JOHN M. FESSENDEN, Engineer. FRAME BRIDGES. PROSPECTUS OF VOLUME II. OF THE CHICAGO AMERICAN, TO BE PUBLISHED SEMI-WEEKLY. In proposing to establish a SEMI-WEEKLY paper an NOTICE TO CONTRACTORS. JAMES RIVER AND KANAWHA CANAL. THE subscriber would respectfully inform the pubPROPOSALS will be received at the Office of the lic, and particularly Railroad and Bridge CorporaJames River and Kanawha Company, in the City of tations that he will build Frame Bridges, or vend the Richmond, from the 15th to the 23rd day of August, right to others to build, on Col. Long's Patent, throughfor the construction of all the Excavation, Embank-out the United States, with few exceptions. The folment and Walling not now under contract, together lowing sub-Agents have been engaged by the funder-der the old title, but with extended dimensions, the with nearly all the Culverts and the greater portion of signed who will also attend to this business, viz. subscriber acknowledges the favors of the past, and the Locks between Lynchburg and Maidens' Adven- Horace Childs, solicits the continued patronage of a liberal public.ture. Alexander McArthur, The reasons that induced him about a year since to John Mahan, establish his weekly paper, operates with renewed Thomas H. Cushing, and increasing force in favor of his present design.Ira Blake, He shall endeavor, as it was originally intended, to make his paper American in all things; and by iden tifying itself with the interests and circumstances of Chicago-which from a recent wildnerness has advanced to a population of thirty-five hundred-and of the rich, extensive, and rapidly developing country of which it is the emporium, he hopes it may "grow with their growth, and strengthen with their strength." The work now advertised embraces the twenty miles between Columbia and the head of Maidens' Adventure Pond, the eight miles between Seven Island Falls and Scottsville, and about twenty isolated sections, reserved at the former letting, between Scottsville and Lynchburg. The quantity of masonry offered is very greatconsisting of about two hundred Culverts of from three to thirty feet span; nine Aqueducts, thirty-five Locks a number of Wastes, with several farm and road Bridges. General plans and specifications of all the work, and special plans of the most important Culverts and Aqueducts, will be found at the oflices of the several Principal Assistant Engineers on the line of the Canal, The work will be prepared for examination by the 25th July; but mechanics, well recommended, desirous of immediate employment, can obtain contracts for the construction of a number of Culverts at private letting. Persons offering to centraci, who are unknown to the subscriber, or any of the Assistant Engineers, will be expected to accompany their proposals by the usual certificates of character and ability. CHARLES ELLET, Jr., Chief Engineer of the James River and Kanawha Company. NOTE. The Dams, Guard-Locks, most of the Bridges, and a number of Locks and Culverts, are reserved for a future letting. Persons visiting the line for the purpose of obtaining work, would do well to call at the office of the Company in the city of Richmond, where any information which they may desire will be cheerfully communicated. The valley of James River, between Lynchburg and Richmond, is healthy. (20-ta18) C. E. Jr. RAILROAD CAR WHEELS AND BOXES, AND OTHER RAILROAD CASTINGS. Also, AXLES furnished and fitted to wheels complete at the Jefferson Cotton and Wool Machine Fac tory and Foundry, Paterson, N. J. All orders addressed to the subscribers at Paterson, or 60 Wall street, New-York, will be promptly attended to. Also, CAR SPRINGS. Also, Flange Tires, turned complete. J8 ROGERS, KETCHUM & GROSVENOR. ALBANY EAGLE AIR FURNACE AND MACHINE SHOP. WILLIAM V. MANY manufactures to order, IRON CASTINGS for Gearing Mills and Factories of every description. ALSO-Steam Engines and Railroad Castings of every description. The collection of Patterns for Machinery, is not equalled in the United States. 9-1y RAILWAY 95 tons of 1 inch by & inch. 200 do 14 do do 40 do 14 da #do IRON. FLAT BARS in lengths of 14 to 15 feet, counter sunk holes, ends cut at an angle of 45 degrees, with splicing plates and nails to suit. 250 do. of Edge Rails of 36 lbs. per yard, with the requisite chairs, keys, and pins. Wrought Iron Rims of 30, 33, and 36 inches diameter for Wheels of Railway Cars, and of 60 inches diameter for Locomotive Wheels. Axles of 24, 24, 24, 3, 3, 34, and 3 inches in diameter, for Railway Cars and Locomotives, of patent iron. The above will be sold free of duty, to State Governments and Incorporated Governments, and the drawback taken in part payment. A. & G. RALSTON, 9 South Front street, Philadelphia. Models and samples of all the different kinds of Rails, Chairs, Pins, Wedges, Spikes, and Splicing Plates, in use both in this country and Great Britain, will be exhibited to those disposed to examine them. 4-d7 Imeowr STEPHENSON, Builder of a superior style of Passenger Cars for Railroads. No. 264 Elizabeth street, near Bleecker street, New-York. RAILROAD COMPANIES would do well to examine these Cars; a specimen of which may be seen on that part of the New-York and Harlaem Railroad now in operation. J25tf | Henniker, N. H. Mount Morris, N. Y. do do Dover, N. H. Wakefield, N. H. Hancock, N. H. Springfield, Vermont. do do Northampton, Mass. Waterloo, N. Y. do Dunkirk, N. Y. Hudson, Ohio. do Lower Sandusky, Ohio. do do As a record of passing events, current literature, of the march of agriculture, commerce and manufactures, and especially of the progress of internal improvements, of which this State, by her recent passage of the act for the construction of the "Illinois and Michigan Canal," has commenced her great and auspicious system, it will aim, as ever, to be accurately and early informed, and thus endeavor to consult alike the tastes and wants of the community with which it is identified. With party, as generally understood, it will have as little to do as possible. Its politics will be the Constitution-its party, the Country. Amos Whitemore, Fsq., Samuel Herrick, Simeon Herrick, Capt. Isaac Damon, Lyman Kingsly, Elijah Halbert, Joseph Hebard, Col. Sherman Peck, Andrew E. Turnbull, William J. Turnbull, Sabried Dodge, Esq., (Civil Engineer,) Ohio. Booz M. Atherton, Esq. New-Philadelphia, Ohio. Stephen Daniels, Marietta, Ohio John Rodgers, Louisville, Kentucky. John Tililson, St. Francisville, Lous'a. Capt. John Bottom, Tonawanda, Penn. Nehemiah Osborn, Rochester, N. Y. Bridges on the above plan are to be seen at the following localities, viz. On the main road leading from Baltimore to Washington, two miles from the former place. Across the Metawamkeag river on the Military road, in Maine. On the National road in Illinois, at sundry points. On the Baltimore and Susquehanna Rrailroad at three points. On the Hudson and Patterson Railroad, in two places. On the Boston and Worcester Railroad, at several points. On the Boston and Providence Railroad, at sundry points. Across the Contocook river at Hancock, N. II. Across the Connecticut river at Haverhill, N. H. Across the Contoocook river, at Henniker, N. H. Across the TERMS. The AMERICAN will be published SEMISouhegan river, at Milford, N. H. Across the Kennebec river, at Waterville, in the state of Maine.- scribing; $5 if paid at the expiration of six months, or WEEKLY, at $4 per annum, if paid at the time of subAcross the Genesse river, at Mount Morris, New-$6 if payment is delayed to the end of the year. York, and several other bridges are now in progress. The undersigned is about to fix his residence in Rochester, Monroe country, New-York, where he will promptly attend to orders in this line of business to any practicable extent in the United States, Maryland excepted. MOSES LONG. General Agent of Col. S. H. Long. 19y-tf. Rochester, May 22d, 1836. PATENT RAILROAD, SHIP AND BOAT SPIKES. With this brief explanation of its future course, and his thanks for the more than expected encouragement he has already received, the subscriber again ventures to solicit the continued patronage and extended support of all who may feel an interest in the principles here set forth. It will be enlarged and otherwise greatly improved, and printed on superior paper, and forwarded to dis tant subscribers by the earliest mails, enveloped in a strong wrapper. **Any person procuring five subscribers and remitting the pay in advance, will be entitled to a sixth copy gratis, or a deduction of TEN PER CENT. Persons at a distance remitting a $5 bill will receive the paper fifteen months. All sums to the amount of $10 and upwards may be sent through the Post Office, at my expense. THOS, O. DAVIS. Chicago, March 25, 1836. Subscriptions and Advertisements for the CHICAGO AMERICAN will be received at the Office of the Railroad Journal, 132 Nassau street, by D. K. MINOR. The Troy Iron and Nail Factory keeps conTHE NEWCASTLE MANUFACTURING stantly for sale a very extensive assortment of Wrought COMPANY, incorporated by the State of Delaware, Spikes and Nails, from 3 to 10 inches, manufactured with a capital of 200,000 dollars, are prepared to exby the subscriber's Patent Machinery, which after ecute in the first style and on liberal terms, at their five years successful operation, and now almost uni-extensive Finishing Shops and Foundries for Brass and versal use in the United States, (as well as England, Iron, situated in the town of Newcastle, Delaware, all where the subscriber obtained a patent,) are found orders for LOCOMOTIVE and other Steam Engines, superior to any ever offered in market. Iron RAILROAD WORK of all kinds finished in and for CASTINGS of every description in Brass or the best manner, and at the shortest notice. Orders to be addressed to Railroad Companies may be supplied with Spikes having countersink heads suitable to the holes in iron rails, to any amount and on short notice. Almost all the Railroads now in progress in the United States are fastened with Spikes made at the above named factory-for which purpose they are found invaluable, as their adhesion is more than double any common spikes made by the hammer. All orders directed to the Agent, Troy, N. Y., will be punctually attended to. HENRY BURDEN, Agent. Troy, N. Y., July, 1831. & J. Townsend, Albany, and the principal Iron Mer Spikes are kept for sale, at factory prices, by I. chants in Albany and Troy; J.I. Brower, 222 Water street, New-York; A. M. Jones, Philadelphia; T. Janviers, Baltimore; Degrand & Smith, Boston. P. S.-Railroad Companies would do well to forward their orders as early as practicable, as the subscriber is desirous of extending the manufacturing so as to keep pace with the daily increasing demand for his Spikes. 1J232m H. BURDEN. ARCHIMEDES WORKS. (100 North Moor street, N. Y.) NEW-YORK, February 12th, 1836. THE undersigned begs leave to inform the proprie. tors of Railroads that they are prepared to furnish all kinds of Machinery for Railroads, Locomotive Engines of any size, Car Wheels, such as are now in successful operation on the Camden and Amboy Railroad, none of which have failed-Castings of all kinds, Wheels, Axles, and Boxes, furnished at shortest notice. 4-ytf H. R. DUNHAM & CO. MR. EDWARD A. G. YOUNG, Superintendent, Newcastle, Delaware. feb 20-ytf NOTICE OF THE NEW-YORK AND ERIE RAILROAD COMPANY. THE Company hereby withdraw their Advertisement of 26th April, in consequence of their inability be let on the 30th June, at Binghampton, and on the to prepare in time, the portions of the line proposed to 11th of July at Monticello. Future notice shall be given, when proposals will be received at the above places, for the same portions of the road. 21-tf JAMES G. KING, President. AMES' CELEBRATED SHOVELS, SPADES, &c. 300 dozens Ames' superior back-strap Shovels AMERICAN RAILROAD JOURNAL, AND ADVOCATE OF INTERNAL IMPROVEMENTS. PUBLISHED WEEKLY, AT NO. 132 NASSAU STREET, NEW-YORK, AT FIVE DOLLARS PER ANNUM, PAYABLE IN ADVANCE. D. K MINOR, EDITOR.] CONTENTS: Editorial Notice: Questions respecting Steam versus Water, Brief Hints for Spring Work, 369 NEW MODES OF HEATING BUILDINGS. What is the best and most economical mode of heating dwelling-houses, schools, Mr. MINOR :-In No. 38, p. 98, of the Magand lecture rooms, factories or other large azine, your correspondent D*** F***** inbuildings? By introducing heated air from quires what is the best and most econom371a furnace-by pipes, heated by steam, car-ical mode of heating large buildings. As 372 ried around the sides of each room, or by 380 similar pipes filled with boiling water? 354 AMERICAN RAILROAD JOURNAL. NEW-YORK, JUNE 18, 1836. We give in this Number, a part of the Appendix to Pambour on Locomotion; it will be concluded in the next number. From the Mechanics' Magazine. What is the requisite size of a furnace to heat a room or a house of any given dimensions? What should be the size of the flue, for warm air, for heating the whole house; and what that of the branch flue for each particular room? What is the best construction for the furnace-pipes, &c. upon the hot air, steam, or hot water plan; and what quantity of fuel (wood or coal) will be consumed per The following Questions, which were pro-hour, if the fire be kept up, day and night, posed in a late number of the Mechanics' upon each plan, and what the cost? Magazine, are, in consequence of some mistakes then made in them, again offered for consideration, with some modifications and additions. QUESTIONS RESPECTING WATER-WHEELS, What are the requisite dimensions of the furnace, boiler, pipes, &c. to be properly proportioned to the size of the whole building and to each room; and what the whole cost? Are pipes of hot water, which are used to such advantage in England, sufficient for the purpose in a country where the winters no one more able has replied to this inquiry, in the succeeding numbers, I venture to trouble you with a few casual observations made by me during a few years residence in London; and to request the publication of them, in case you think them likely to be of sufficient use to warrant their appearance in your valuable work. All the methods I have seen may be divided into two classes,-those in whic water intervenes between the fire and the atmosphere, and those in which the fire is uncovered, or separated from the atmosphere merely by plates of iron. To the second of these there is a well known objection, that the quality of the air is injured by contact with heated iron, in so great a degree as to cause headache and unpleasant sensations in the eyes and even in the skin generally. By some this is said to be owing to a change in the electric state of the Can a stream of water be used to as much are so intensely cold as ours sometimes are? air; by others, to the absorption of oxygen advantage, or made to do as much work, upon a horizontal wheel as upon a vertical one; and if so, what is the best construction for one, and what the cost of building it? Can the same quantity of water that is let, in a thin sheet, upon a vertical wheel, (that is a wheel upon a horizontal shaft,) be made, in any way, to produce the same effect, when let in solid column upon a horizontal wheel, on a vertical shaft? What have been the results of the experiments upon water wheels, made under the direction of the Franklin Institute, at Philadelphia? What kind of wheel was found best adapted to, or most effective under any given head and fall? D*** F*****. by the heated metal:-the remedy they both propose is, to evaporate water; but it has not been shown to my satisfaction, that this The following communication is in reply entirely removes the evil, or that it does to some queries published in a late number, not introduce a dampness that is not aland now re-published in consequence of ways desirable. Besides, this principal obseveral errors in the first publication. The jection, there are frequently gases, dust, information it furnishes appears to be the smoke, and unpleasant odors, arising from result of the observations of a practical stoves and open fires, and particularly from man. those complicated and expensive rattleWe may here remark that some success-traps, called air-furnaces. From my own ful observations on heating by steam, are contained in a work, lately received by us, and from which we shall extract much interesting matter on this and other subjects, as soon as we can dispose of the matter al. ready on our hands. observation, and from the verbal reports of many who have used them, and from all that I have read on the subject, it appears that the first class of contrivances are not liable to injure the air, as the others do, by giving it the power of causing headache, |