the boiler below the lowest level of the water, the other above the highest, so that steam only shall pass through the latter.

When the engines have external cylinders, the exhaust-pipe divides into two branches. The injection-tube must therefore have also two branches; one going to the under side of each branch of the exhaust-pipe. The bifurcation should be perfectly symmetrical, so that the water held in suspension in the steam may not take the line of steepest descent, and that the distribution to each cylinder may be equal."

CAR-WHEELS.

From Auchincloss' Report of the Paris Exhibition we extract the following: :

"The practice of nations seems much divided on the subject of the proper material for car-wheels. The_wrought-iron wheel is almost exclusively adhered to in England, France, and Prussia; while Holland and Austria discover features worthy of attention in the cast iron. The general properties of the cast-iron spoke wheel are familiar to all. The society of Providence (limited), whose office is at 208 Quai Jemmapes, Paris, display specimens of rolled wrought-iron wheel centres, without weld, whose radial section is similar to an I-beam. Upon such centres the tire is held with 4 seven-eighth inch rivets.

"The Society of Mines and Steel Works, Bochum, Prussia, exhibits a remarkable cast of wheels. It was formed by stacking the flasks 22 wheels high, with the hubs in contact, and then pouring in crucible steel through a side-runner. Although this cast was made more as a matter of curiosity, it is quite customary with this company to arrange them in tiers of 6 wheels each, and thus save the numerous side-runners required when cast singly. One swinging of the set in the lathe answers for facing up all the treads and flanges. These wheels have a single plate, and are 40 inches in diameter. The Austrian exhibitions are by A. Ganz, of Ofen, Hungary, and Mr. Derno, of the same section of country. The former gentleman is the most extensive manufacturer in Austria, and makes a double-plated wheel, similar in design to that known in America as the Snow Patent.' He exhibited a wheel 38 inches in diameter, cast in 1856, which has served under a 10 ton four-wheeled wagon for the past 11 years. The tread of this wheel appears in excellent condition, the metal close-grained without signs of honey-combing.

"The director-general of the Austrian I. R. P. State Railway Society certifies to the fact of this wheel having run 50,000 miles. The road on which these wheels are used is 419 miles in length, and pursues a south-easterly course from Vienna through Hungary. In respect to climate the trial is most severe. Its merits are certainly appreciated or the shop number would not extend as high as 84,981, which was noticed on a wheel cast during the present year. The wheels, as usual, have 3 core-holes in the back. The only peculiarity about these holes is a V-groove cast

near the opening, into which, when the core is removed, an eighth of an inch sheet-iron disk is sprung. This method is employed on wheels designed specially for passenger coaches, and prevents the entrance of stones, which, rattling within a wheel of so large diameter, become a source of much annoyance.".

WOODEN WHEELS.

The directors of the New York and New Haven Railroad have decided, as an experiment, to use wooden wheels on some of the cars upon their road. Quite a number of these wheels have been purchased, and will be substituted for the present iron ones on some of the new cars. They are understood to cost nearly treble the price of iron wheels, but are considered quite as cheap in the end. They are made of elm or teak wood, and bound with steel tires. Besides being less liable to break by the action of frost, they make less noise.

SLIDING OF CAR-WHEELS.

An experiment has been made at Munich for the purpose of determining if a railway-carriage wheel rolls regularly without sliding, so that by recording the number of revolutions of a wheel, the circumference of which is known, the distance accomplished could be accurately ascertained. The difference between the measurement by mathematical instruments and that obtained by noting the revolutions of the wheel was found to be no more than one sixty-eight thousandth of the whole.

A NEW ALARM-BELL FOR LOCOMOTIVES.

A new alarm-bell was tested on the Detroit and Milwaukie Railroad lately. The invention consists of an ordinary bell, weighing about 100 pounds, placed on the platform of the locomotive, immediately over the cow-catcher. A rod attached to the eccentric shaft causes a clapper to strike the bell each turn of the driving-wheel. The bell is suspended loosely, and revolves from the force of the stroke it receives, so that all parts of the surface are equally exposed to wear. The advantages of this arrangement are a continuous sound, slow or rapid in proportion to the speed of the engine, each 15 feet producing a stroke of the bell. In case of an accident, the railroad company can always prove that their bell was ringing according to law; and owing to the position in which this bell is placed, the sound can be distinctly heard about 3 miles in daytime, and by night 4 miles or more, the ground and the continuous rail, both excellent conductors of sound, assisting in carrying the vibrations. The Detroit and Milwaukie Railroad have 24 of these alarms already in use, and intend to provide all their passenger-engines with

them.

IMPROVED TRACTION UPON STEEL RAILS AND STEEL-HEADED RAILS.

It has been too much the practice of railway managers to consider only the increased durability of steel. A less striking, but perhaps equally important advantage, is that it has double the strength and more than double the stiffness of iron. Some 3 years since, Mr. George Berkley made, in England, above 600 tests of the stiffness of steel and iron rails of equal section. The rails were supported on 5-feet bearings, and loaded with dead pressure at the middle. The first rails tried weighed 68 pounds per yard, and loads respectively of 20 tons and 30 tons were applied. The average of 427 tests of the Ebbw Vale Co.'s and two other standard makers of iron rails, gave, with 20 tons, a deflection of five-eighths inch and a permanent set of one-half inch. With 30 tons the deflection was two and one-fifth inch and the permanent set two and one-sixteenth inch. With Brown's steel rails, 45 tests gave an average deflection of but five-sixteenths inch and permanent set of one-eighth inch. With heavier rails and loads, the comparative stiffness of steel was still more marked. The great and constant resistance of traction, and the wear and tear of track wheels and running gear, due to the deflection of rails between the sleepers and the perpetual series of resulting concussions, may be much reduced, or practically avoided, by the use of rails of twice the ordinary stiffness; in such a case, however, reasonably good ballasting and sleepers would be essential. When a whole series of sleepers sinks bodily into the mud, the consideration of deflection between the sleepers is a premature refinement. If the weight of steel rails is decreased in proportion to their strength, these advantages of cheaper traction and maintenance will not, of course, be realized. The best practice, here and abroad, is to use the same weight for steel as had been formerly employed for iron.

Many attempts have been made in England, on the Continent, and in this country, to produce a good steel-headed rail, and not without success. Puddled steel-heads have all the structural defects of wrought iron, as they are not formed from a cast, and hence homogeneous mass, but are made by the wrought-iron process, and are, in fact, a “high,” steely wrought iron. They are, however, a great improvement upon ordinary iron, although probably little cheaper than cast-steel heads. Rolling a plain caststeel slab upon an iron pile has not proved successful. The weld cannot be perfected, on so large a scale, and the steel peels off under the action of car-wheels. Forming the steel slab with grooves, into which the iron would dovetail when the pile was rolled into a rail, has been quite successful. The greater part of some 500 tons of such rails, made in this country, and put down where they would be severely tested, about 4 years ago, have outworn some 3 iron rails. Others failed in the iron stem, which was too light, after a shorter service. Rolling small bars of steel into the head of an iron pile has been recently commenced

at various mills in this country and in England. No conclusions are yet warranted by the short trial of these rails.

There is a growing feeling among engineers and steel-makers that the compound rail, made wholly or partly of steel, will prove more safe and economical than any solid rail, and that the defects of the old compound iron rail, largely used in this State some years since, may be avoided, since these defects were chiefly due to the nature of the material. The experiments in this direction will be watched with great interest by railway managers, for if the same durability of track can be obtained with a steel cap as with an all-steel rail, the first cost will be greatly decreased. A rail made in two or three continuous parts, breaking joints, is also a practical insurance against disaster from broken rails. State Engineer's Report on Railroads.

NARROW GAUGE RAILWAY.

The Portmadoc and Festiniog Railway, Wales, is now attracting much attention from railroad men. This is a little line in North Wales, which was originally constructed for the purpose of acting as a tramway for slate and stone from the hills of Merionethshire to the sea-shore. It is now being used as a regular goods and passenger line. The chief peculiarity in its construction is that the gauge is only two feet broad. Hence, though the line runs through a very difficult country, the expenses of construction and working are so small that the traffic yields the enormous revenue of 30 per cent. The reason is simple enough. It is because the proportion between the dead weight and paying weight is so much less than upon other railways. The engine and tender upon this line weigh about 10 tons, against 40 tons upon the wider gauge of other lines. Instead of a first-class carriage, weighing 7 tons, to carry 32 passengers, and representing nearly 5 cwt. of dead weight for each passenger, the carriages on the Festiniog weigh only 30 cwt. for 12 passengers, or two and a half cwt. for each person carried.

The annual report of the State Engineer of New York, prepared by S. H. Sweet, Deputy Engineer, contains the following regarding steel rails: "Bessemer steel rails have been in regular and extensive use abroad over 10 years. For some 5 years large trial lots have been laid on various American roads having heavy traffic, and during the last two years importations have largely increased. The manufacture of steel rails has also been commenced at four large establishments in this country, and some 7,000 tons of home manufacture have been produced and laid down. It is estimated that from 40,000 to 50,000 tons of steel rails are in use on our various railways. Among the users of steel rails are the Hudson River, Erie, and Pennsylvania Railway, 10,000 tons or more each; the Lehigh and Susquehannah (entirely

built of steel); also the Philadelphia and Baltimore; Camden and Amboy line; Lehigh Valley; New York Central; New York and New Haven; Naugatuck; Morris and Essex; Cumberland Valley; South Carolina; Chicago and North-western; Chicago and Rock Island; Chicago and Alton; Michigan Central; Lake Shore line; Chicago, Burlington, and Quincy; Pittsburgh, Fort Wayne, and Chicago; also the Boston and Providence, Boston and Worcester, Boston and Maine, Boston and Albany, Eastern, Connecticut River, and other lines in New England.

"The Wear of Steel Rails. As no steel rails are reported to have worn out on our roads, the comparative durability of steel and iron cannot be absolutely determined. The president of the Philadelphia and Baltimore Railway states (in the letter before quoted) that the use of steel commenced in 1864, that the rails (25 miles in all) were laid on the most trying parts of the line; that none have been taken up on account of breakage, wear, or defect; that upon the portion of the line near Philadelphia the first steel rail imported had already worn out 16 iron rails; and that none of the steel rails have shown any imperfection, but are all wearing smoothly and truly.

"On the Pennsylvania Railway, the report of the Chief Engineer for 1868 states that 11,494 tons of steel rails had been purchased, and 9,656 tons laid. The first were laid in 1864. They are all wearing smoothly, showing no change except the slight diminution of section to be reasonably expected from the heavy traffic. No steel rails have yet worn out. The report of the superintendent (Feb., 1869) says: The use of steel rails continues with satisfactory results, and 4,544 tons of this material have been laid since date of last report.' It is officially reported that on the Camden and Amboy line some of the steel rails laid 3 years ago are now good in places where iron lasted but a few

months.

"The last report of the Engineer of the Lehigh Valley Railway says: Another year's wear has made no perceptible impression upon the 200 tons (of steel rails), the first of which was laid in May, 1864, none of which has broken or given out since last report. These rails have had a severe test, being in those places in the track where they are subject to the greatest wear, laid with a chair, which is much inferior to the most approved joint now in use. There is no longer any possible doubt as to the superiority of steel over iron in economy, as in every other respect.'

"Unofficial reports from the Erie, Hudson River, and other roads, show that the above statements represent the average quality of steel rails. The last report of the New York and New Haven Railway states that the subject of steel rails has received special attention, and after a careful investigation of all the points involved, it has been determined hereafter to make all renewals of track with steel rails only; 2,900 tons of Bessemer steel rails have been contracted for on account of renewals for the present year.' The report of the Morris and Essex Railway for 1868 says: During the last year one track through the tunnel has been relaid with steel,'- also some 150 tons of steel laid elsewhere.