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the substructure just now, but some idea of the magnitude of the work may be gleaned from the fact that 300,000 cubic yards of excavation had to be accomplished, about live miles of girders placed in position, and upwards of five square acres of asphalte spread over the concrete on the arches and walls, all of which has been executed in a space of time so short as to be unprecedented in the annals of the profession. A new road 60ft. wide is formed on the north side of the market building, and continued westward to meet Farringdon-road, and roads of the same width have been made on the east and west sides. A public roadway, 50ft. wide in the clear, passes through the centre of the markets from north to south, thus connecting Smithfield with St. John-street-road.

The section on page 448 shows the mode of construction from the girder beneath to the ridge; the shops are subdivided by wrought-iron framing. The front shops open to the main roof, and in them the meat is exposed for sale. After business hours the stock can be removed into the back shops, which are enclosed by steel revolving shutters. At the rear of the back shop is a small office or counting room, from which winding stairs lead to a retiring room on the second floor. This lastnamed room is a great boon to tenants of shops as a place to take their meals or transact their private business free from interruption, and has given great satisfaction to the tradesmen interested in the matter. On the upper floor, W.C.'s and lavatories are provided; over this is a light roof, between which and the main roof of the building ample ventilation is afforded. The illustrations on pages 450 and 451 of the gateways, is so clear in its details that comment is rendered unnecessary, as its construction and beauty can be seen at a glance. We shall continue our illustrations on this subject next week.

THE

ANOTHER "GREAT EASTERN." HE robable construction of a sister ship to the "Great Eastern" is reported from the other side of the Atlantic, one having been designed by a Mr. Thomas Silver. She is to be of the same size as

per cent.

MACHINERY FOR MANUFACTURING
NAILS AND SPIKES.

The method employed to test this irregularity of motion was by means of a pencil making a series of marks, one at each rotation of HE accompanying engraving illustrates an inven the fly-wheel, across a long strip of paper, which company enged by Mr. John Carter, of was slowly unwound from a reel by a regular Ladywood Dock, Birmingham, for an improved motion. The variation of space between the lines method of manufacturing nails and spikes. In mathus produced exhibited the variation of time chinery constructed according to this invention the between the revolutions of the engine. The oscilla-pointing of the rod, the cutting off of the pointed [tion of the engine as it is getting into speed was rod, and the heading of the cut-off rod, are done in also indicated by this apparatus. The chairman the same machine, although these improvements in gave a description of a self-regulating stove, in pointing may be applied to machines which effect which this oscillating movement was seon until it the pointing separately. In our illustration, fig. 1 represents in front elevation Mr. Carter's machine for was regulated, and observed that this oscillation of the manufacture of nails and spikes; fig. 2 is a plan motion was apparent in all self-regulating machines. of the same, the covering plate being removed; Mr. Emery made some remarks upon the import- fig. 3 is a longitudinal vertical section taken ance of clearance at the end of engine cylinders; through the middle of the machine; and fig. 4 as much as one inch and a-half had been formerly is also a longitudinal vertical section taken through used, and he deemed it necessary that the ratio of the heading punch; figs. 5, 6, 7, 8, 9, and 10 repremotion to resistance should be better understood. sent the principal tools of the machine. He also thought that the so-called economy due to the cut-off was much exaggerated. Leakage of steam past the piston when in motion was another evil, and much loss of power was occasioned by condensation of the steam in the cylinder, but this evil could be somewhat remedied by jacketing and superheating. He had observed that the best method of regulating the speed of the engine was by means of rotating fans or vanes, and for this purpose he had used the Dimpfel blower with very good success.

A DANGEROUS SHOAL APTAIN KEMPTON, of the bark "Java 2nd," "New York Herald":-On my passage from Singapore to Samboangan, after passing through Balabac Straits, I steered to pass between St. Michael's Island and the Island of Bancarin (I have James Imray and Son's chart). At 7 p.m. was surprised at seeing bottom alongside; cast the lead, and got 6 fathoms, coral. There being a very light air at the time, stood along apiece and got 5 fathoms. Lowered a boat and went around and found out ahead of the ship quarter less 5 fathoms. I let go my anchors and laid there during the night. The next morning, it being calm, I took the "Great Eastern," except that instead of 28ft. a boat and sounded on different parts of the reef; she will draw only 18ft., and she will carry pro- in some places I got as little as 24 fathoms; portionally less tonnage. She is designed to carry the most water 5 and 6 fathoms; it appeared to be four times as many passengers as any present style steep, too, on the side I was on, the south edge, as of ship, and to substitute for bunks Christain beds; in about two ships' lengths, it deepened from 5 to she will also give four times the space to a state-25 fathoms. The southern edge of the reef made room. The present mode of bunking passengers is unworthy of the age. Sea-sickness, if preventible by construction, should be rendered obsolete. This desideratum is said to be attained in Mr. Silver's coming ship; it is secured by the proportions of the ship, and by there being 30ft. less of the hull out of water than in the "Great Eastern;" but the motion is rendered almost imperceptible by a new device. The state-rooms, instead of being at the outside limits of the vessels, are amidships, that is, along the centro line of the ship, where the roll is scarcely perceptible. The saloon is to be 500ft. long, and clear of obstruction. It is not for dining. Instead of a public table, there are to be two competing restaurants at the extremities adjoining the saloons. The ship will sell passage only, the board being payable as meals are ordered. It is contemplated to carry second-class passengers and third-class in the same way. The present first-class bunks will be for third-class berths. May her career be more prosperous than that of her prototype.

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TESTING STEAM ENGINES.

about S.E. and N.W.; I went to masthead and
looked over it, and should think it N. and S. about
half a mile, N.W. and S.E. about a mile.
By
observations I made, it is in lat. 7 52 N., iong.
118 28 E., not very good observations, as it was
cloudy and overcast weather. The most northern
of the St. Michael's Islands bore S.W. by S. S.;
the Island of, Bancarin N.E. N., and Mount
Mantaleengahan (on Palwan) N.W. 9 a.m. a breeze
sprung up; took up our anchor and stood to S.E.
between the reef and the most northern portion of
St. Michael's Island. Saw no more dangers.

STEAM ON STREET RAILWAYS. NEW method of applying steam for locomotive purposes on street railways, so as to avoid the use of fire in the engine while running on the streets, is reported in the "Philadelphia Ledger" as having been exhibited on a temporary track. In this engine the necessity for a fire-box, smoke-stack, &c., is done away with by substituting a strong tank or reservoir for holding water previously heated to a high temperature in a stationary boiler. The water so heated is forced into the locomotive tank, and is capable of giving off an amount of working steam for a considerable length of time sufficient to

steve the engine and draw

The

We will first describe that part of the machine by which the pointing of the rods is effected. a is the pointing roli fixed on the shaft; b the position of the roll being adjusted by means of the adjusting screws c, the lower ends of which bear upon the brasses of the shaft b. Working underneath the roll a is a travelling tool box or bed d, in which an inclined pointing tool e e e 3 is carried. The construction of the travelling tool box or bed and tool will be best understood by referring to figs. 5, 6, and 7, fig. 5 representing a longitudinal vertical section of the box or bed and tool, fig. 6 an end elevation, and fig. 7 a plan of the same. The tool box or bed d consists of a metal trough, to one side of which the plate e is screwed, and to the inner face of the plate e the acting face e 3 of the tool is screwed. The shape of the part 3 and its position between the The opposite side of the trough to that at which the plate e is fixed is cut away, and in the cut away part the other plate e 2 of the pointing tool is secured. The plate or part e is capable of turning on the pin or centre e, so as to increase the distance of the part e 2 is limited by a pine passed into the between it and the fixed part e of the tool. The motion bed d working in a slot indicated in dotted lines in

the

e e 2 of tool are best seen

part e 2. The periphery of the roll a works in the slot formed between the two parts e e 2 of the pointing tool. When worn, the acting inclined part 3 of the tool may be removed and replaced by a fresh one, or a larger or smaller one substituted, according to the size of the nails or spikes to be made, or the slot between the tool may be made of greater or less working width by the introduction of separate side packing pieces.

The roll a performs a rotary motion, and the travelling bed d a reciprocating rectilinear motion. The travelling bed works in a slot in the cross plate f fixed to the framing of the machine. The free and front end of the travelling bed d is supported on a cam g on the shaft h under the roll shaft b, and the bed is supported laterally by the collars in on the shaft h. The advance motion of the bed d is effected by the friction of the nail rod between it and the roll a, the bed being raised and pressed against the nail rod and roll by means of the cam g on the shaft h. The return motion of the bed is effected by the spring 1; the movable part e of the pointing tool is closed and supported in its place during the pointing operation by means of a projection m on the collar n acting against the outer side of the part; is a stop against which the nail rod is fed, the stop being carried by the cross plate f. The heated nail rod p to be pointed is introduced into the inclined the stop o. slot at the fore end of the pointing tool, and against into the slot of the pointing tool is permitted by the The easy introduction of the nail rod position of the travelling bed with respect to the roll yielding of the movable part e 2 of the tool, and the a, that is, when the travelling bed is in the position proper to receive the nail rod, the rise of the cam g is withdrawn from underneath the bed d, and the bed is depressed from the roll by the action of the cam i 2 où the collar k upon the bed (see fig. 4).

A Branch T the weekly meeting of the Polytechnic The nail road p having been fed into the slot of the travelling tool in the bed, the projection m of York, held on Thursday evening, November 5, new locomotive weights about five tons when fully the collar a comes into operation, and keeps the Professor Tillman in the chair, the subject taken supplied with the requisite storage of heated water. movable part e 2 of the tool to its work, and the cam At the trial it ran 45 minutes, making 125 stoppages,g also comes into operation, and raises the travelling was the best modes of testing the power and and reducing the steam pressure from 801b. at start- bed and its tool towards the roll a, and makes the economy of steam engines," which had been dis-ing to 201b, when the trial ceased. No noise was roll enter the slot in the tool (see fig. 1). By the cussed at a previous meeting. Mr. Stetson re- made other than the rumble of the wheels over the action of the roll a and travelling tool in the bed d, marked that much had been said upon the subject rails, and the machine seemed to be at all times the end of the heated rod p is compressed between of economy in the engine, but the importance of under the perfect control of the engineer, being the periphery of the roll and the inclined end of the "regulation" had been entirely overlooked, and stopped almost instantly while running at the rate tool, and the required taper figure given to the rod, much information was desirable upon this subject, of six miles per hour. The temperature of the the lateral spreading of the metal during the taperespecially as regards the stationary engine. He water is kept up by a non-conducting jacket three ing of the rod being prevented by the sides of the instanced weaving, in which looms or lines of shaft- inches thick around the tank. It is proposed, in slot in which the roll works. As the rod is pointed ing are connected or disconnected instantaneously, adapting the invention to the street cars, to place a it is delivered back to the workman. In fig. 3 the where it is of the utmost importance that the speed stationary steam boiler at the end of the road to rod p is represented in the position it occupies just charge the locomotive with a sufficient quantity of before the pointing operation is completed. After be kept regular and constant. He observed that hot water to perform the trip. This idea was the experimants made by the American Institute advanced by Mr. W. T. Carrington CE, in his of the cam g and projection i 2, and the projet on m the pointing of the rod, the bed d falls by the action in June, 1858, had never been published. He had inaugural address as president of the Society of ceasing to act upon the part of the pointing tool, prepared an elaborate report, and an abbreviated Engineers for 1865. the pointed rod may be readily removed from the one, the latter of which was published in the pointing tool. The travelling bed d being returned by "Practical Mechanics' Journal" in 1858. Of the the spring to its original position, another nail rod is two engines tested at the Fair in the trial referred introduced into the tool in the bed d, and the operato, the variation had been as much as twenty-eight tions described are repeated. The distance between

THE new series of experimental firing at Fort
Monroe was expected to begin about the 20th ult.

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the two collars in, between which the travelling bed works may be adjusted by means of the set screw h 2 acting on the collar n.

We now come to the machinery by which the cutting off of the pointed end of the rod and heading of the cut-off lengths are effected. The pointed rod marked p 2 in fig. 2 is taken from the pointing machinery, and passed through an opening q in the framing of the machine, and introduced between the fixed and movable cutters rs (see fig. 3), and also between the two dies t t 2, the dies being sufficiently open to receive the nail rod. One of the diest is provided with a stop t 3, against which the end of the p 2 is fed. On the die t 2 is a rest or support t 4, on which the nail rod p 2 is supported on being fed between the cutters and dies. This rest tworks in a slot in the die t, and together engages the two dies. The die tis shown separately in front elevation in fig. 8, and the two dies t t in end elevation in figs. 9 and

rod

10. The dies t t 2 have both a lateral or transverse motion, the die t being forced towards the diet? by the coiled springs t5t5. The distance to which the die t can advance towards the die d 2 is limited by means of pins uu on the die t working in slots in a

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covering plate (see figs. 3 and 4). The covering plate is removed in fig. 2 for the purpose of better exhibiting the working parts. By means of the pins u u and slots in the covering plate v, the die t (when the two dies t t 2 are in the positions represented in fig. 2) cannot completely close upon the die d 2, the dies being open sufficiently to receive the nail rod. The nail rod P 2 having been fed into the dies tt2, the diet closes upon the die t, and the nail rod is gripped between them. This closing of the die t 2 is effected by the transverse slide w,connected with the die t 2. The slide w is actuated by the cam r on the end hafty, through the lever z 2, longitudinal slide z, and link 1. The slide and lever z are pressed against the came by the coiled spring x 2. The nail rod p 2 being gripped at its shank (the pointed end being protected by the cut away part of the dies), the movable cutter s descends and cuts off the required length of the rod between the movable cutter and the fixed cutter r. The movable cutter s is carried by a Z-shaped vertical slide 2, working on opposite sides of the part 3 of the framing (see the plan, fig. 2, and section, fig. 3), The advance motion of the cutter s is effected by a cam or projection 4 on the shaft, acting on the hook-shaped projection 5 on the slide 2. The return motion of the cutters and slide 2 is effected by a spring. The cut-off length of rod gripped between the dies t t 2 is carried by the lateral or transverse motion of the dies in front of and in a line with, the heading punch 6, as represented in fig. 4, where the cut-off length of rod is marked 19. This lateral or transverse motion of the dies tt 2 is effected by the continued action of the came upon the lever 2, slide z, link 1, and slide w, and the latter upon the dies t t 2. The cam r is thus made double-acting, that is, its first action is to close the die t 2 so as to grip the nail rod, and its next action is to advance the two dies with the cut-off length of rod between them in front of the heading punch 6. By the advance of the heading punch. 6, the punch enters the front end of the dies, and compresses the end of the rod into the countersink of the dies, and thereby forms the head of the nail or spike.

2

THE

STREET RAILWAYS.

The

HE accompanying engraving illustrates a system of street railways proposed by Mr. Haworth. It consists in laying up-and-down lines of rails in all public roads of great traffic where five yards in the centre of the roadway can be appropriated for omnibus and other fast traffic. carriages running off on the near side to set down London drivers always have their horses well in or take up, neither flanges or guides are used. The hand, and their pole chains tight, and are accustomed to drive to an inch. They will be able to sight the end of the pole with the guide rail, and thus keep the track. After a few journeys the horses will find out that there is no road resistance, no macadam to grind, nor jolting over uneven pavement; all resistance will be a question of weight.

LIQUID FUEL FOR IRON MANUFACTURE.

LTHOUGH is ascertained there was

to five times the amount of work could be done with

SO

Auch Gaggiation in the statements made at the time of the first attempts to introduce liquid fuel, to the effect that one ton of oil could be stowed in onetenth the space required for coal, and that from four the former as with the latter, equal weights being used, the assertions had the advantage that they served to invest the subject of burning liquid fuel with an interest which otherwise it would, probably, never have obtained. After innumerable failures common to all efforts to introduce improvements, the burning of liquid fuel has now been brought into practical working order, its use being now throughly understood that it can be controlled to the greatest nicety. The complete substitution of liquid fuel for coal is now recognized as impracticable; but in making the tests which have led to this conclusiou it has been demonstrated, under certain circumstances, and for certain purposes, that liquid fuel possesses advantages, of the most important character. There are many instances in which a clear and unvarying gas flame can be so beneficially turned to account, that even were extra cost incurred it would be desirable to employ it, so that its production at a materially lower rate than that which would be incurred to obtain the same amount of heat with coal, cannot fail to lead to its very general adoption in those cases.

In referring to the application of Mr. Edward Dorsett's invention to the generation of steam for marine purposes, it has been already stated that the inventors had succeeded not only in obtaining better results than had before been obtained with liquid fuel, but that the value of the arrangement was further proved by the fact that the maximum theoretical efficiency had been very nearly reached. This was confirmed by the report of Dr. Paul, made after witnessing a series of carefully made experiments of several hours' duration. Taking the chemical composition of the fluid used, it appeared to possess a maximum evaporative power of 13-0231b. (converting water at 60deg. Fahr. into steam at 212deg.) and in the practical trial in question an evaporative duty of 12.356lb. was obtained, being By an examination of fig. 8 it will be seen that in within little more than half a pound of the maximum. addition to the countersink 7 in the dies in which As the result of his investigation, Dr. Paul conthe head of the nail or spike is shaped, the dies are cluded that with some additional care to regulate the provided in front of the countersink with an open-supply of air and other minor details an evaporative ing 8 in which the punch 6 accurately fits. By this efficiency of 131b. of water per 1lb. of oil burnt means the metal is prevented from spreading during might be attained, so that, taking the average duty the formation of the head of the nail or spike, of coal at 71b. of water evaporated per 1lb. of coal, and the head so made is free from the burr or fraise the weight of oil required to fuel a vessel would which the heads of machine-made nails or spikes only be about one-half that required of coal, or the usually have. The advance motion of the heading weight of fuel to be carried would be only half as punch 6 is effected by the cam 10 on the shaft y act- much as when coal is used. And taking the ton of ing upon the lever 11, and the return motion of the coal as stowed on board a vessel to occupy 43 cubic punch is effected by the spring 12 connected to the feet, and the ton of oil as occupying 34 cubic feet, free end of the lever (see fig. 4). On the retiring of the quantity of oil equivalent to 1 ton of coal would the heading punch 6, the slide wand die t 2 are with-occupy only about 17 cubic feet, so that the saving drawn by the action of a spring, when the finished nail or spike falls from the dies. A knocker-off may be employed to remove the nail or spike should it stick in either of the dies. As the die t2 retires with the slide, it is followed by the die t, which is pressed up by the springs t 5 t 5, until the two dies assum nearly the position represented in fig. 2, when the dies are ready to receive another pointed nail rod, and the machine is ready to perform the operations already described. The diet, slides and z, are kept in their proper relative positions by means of the wedge 13 (fig. 3).

in stowage space would amount to 60 per cent. of the space required for coal.

The excellent results obtained in the generation of steam naturally led Messrs. Dorsett and Blythe to consider whether, by the use of their improved apparatus, liquid fuel could not be substituted for coal i some of the more delicate processes of iron manufacture, and the result has fully justified their anticipations. An ordinary re-heating furnace of large size is now in constant use at the works of Messrs. Camroux and Co., engineers and boiler manufacturers, at Deptford Creek, in which creosote is the only fuel employed, and its working has given complete satisfaction. By the use of the improved furnace a fine clear flame entirely envelopes the plate or angle, or other form of iron being heated. Under ordinary circumstances the iron is ready for fashioning in little more than half the time required when coal is used; and, as the heat is equal in every part of the furnace, it is never requisite, as sometimes happens with coal, to replace the metal in the furnace to complete the shaping of it, and the THE "Phormio of Terence will be the West-finished article, be it a boiler, a fuunel, or what not, minster Play for this year. The rehearsal will take is produced with the metal much less fatigued place on the 10th iust., the principal performance on than usual. As an example of the facility with he 15th, and the final representation on the 17th.] which the new arrangement is applied to existing

The motions of the shafts hy and b are taken from the driving shaft 14 in the following manner :-On the shaft 14 is a pinion 15, which gears with a toothed wheel 16 on the shaft h, and the toothed wheel 16 gears with a toothed wheel 17 on the shaft On the opposite end of the shaft h is a pinion 17, which gears with another pinion 18 on the shaft b.

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furnaces, it may be mentioned that even the door of the fire-chamber has not been removed. The creosote is converted into vapour in an auxiliary boiler, in the usual way, and the vapour supplied through a coil of pipe which takes the place of the usual fire, the supply of vapour requisite to produce in the same way and as easily as the supply of the desired heat being regulated by a stop-cock, illuminating gas to an ordinary burner. The application of liquid fuel to a re-heating furnace is an Messrs. Dorsett and Blythe may well be proud, and advance in connection with the subject of which it is to be hoped it is but the commencement of its application to a large number of industrial purposes "Mining Journal.'

FIRE-PROOF BUILDINGS.*

IRE-PROOF construction has become a matter of

it is interesting to note the improvements from time to time instituted, and how they are carried out. Any method tending to cheapen such buildings, is an invitation that many real estate owners would avail themselves of. Under the present method of design and execution in this city, fire-proof building is such an extravagant luxury, that rarely any private party can indulge in it, leaving such desirable improvements in the hands of wealthy corporations. Of course such a mode of building always must be more costly than where timber is used; but there is no reason in the world why it should present such an item of expense as in the city of New York. As yet few, comparatively, have been built, but many more aro wanted and would be built, could owners be brought to believe that the examples before them, and from which they naturally form their opinions, are monuments of a shameful and wicked extravagance.

Iron is a material of infinite service, when properly and intelligently used, but a very dangerous material in the hands of ignorance or dishonesty. Its nature is such that we can more nearly work to its theoretic limits than can be done with any other material of constructions. The specific gravity of iron is so high that all used over and above what is required for performance of duty, rolls up very rapidly a very costly excess. It is of very recent date that solid rolled beams of wrought iron have been used for floor joists, before which time cast-iron beams had been largely used, especially in England. Many accidents have proved their unreliability, and beams built of plates and angle iron irons were substituted. In this country, the Cooper Institute was the first thoroughly fire-proof building ever built, the beams for which were rolled at Trenton. These beams were 9in. deep, and were rolled from a single "pile," and it seems were necessarily about the largest beams that could be made by that method of piling. Not long after, Mr. John Griffin, of the Phoenix Iron Company, invented and patented a plan by which beams could be solidly rolled up to at least 20in. deep, and as long as would in any event be required. Mr. Griffin's invention consisted in rolling flangebars separately, piling the plates to form the web between them, and then rolling and welding the whole mass together. It may be interesting to note that this process was pirated by the English manufacturers, and is in vogue with them to this day. It is, perhaps, the only method by which beams of large sections can be successfully made. We believe, in Pittsburgh, they profess to make their beam piles by placing channel bars back to back, and thicken up the flanges, when desired, by piling plates on the top and bottom. At present, rolled beams are manufactured in this country, at Phoenixville, Buffalo, Trenton, and Pittsburgh. The two former makes beams. under the Griffin patent, running through a list of sizes from 5in. up to 15in. in depth, and perhaps make the greater proportion of beams used in this country. Trenton and Pittsburgh works use different piles, the former endeavouring to compete with Buffalo and Phoenix by means of the old manner of piling, the latter using channel bar piles. Neither of these works, so far as we know, have been very successful in making beams over 10in, or 12in. in depth.

The supports for beams and girders have been always cast-iron columns; but the wrought-iron hollow columus are gradually being appreciated. A building may be fire-proof, and yet not indestructible. For example, a building may be filled with a combustible material, which, burning with an intense heat, will so unequally strain the iron supports and flooring, that they must yield and carry with them to destruction everything under their influence. This is especially true where cast-iron columns are used, which, when overheated, become as brittle as glass, and shiver, like glass, to atoms, should water be thrown upon them. Such columns will stand no great tension, or any unequal straining, and ought to give place to wrought-iron ones, especially in warehouses or other buildings used for general storage purposes. Office buildings not being subject to the conditions of a warehouse, can have cast-iron columns to support the girders, and with good advantage. Attempts have been made to arrange a

*Journal of the Franklin Institute,

water circulation in the interior of columns to keep
them cool in case of fire among store goods, but we
have heard of no success attending the effort. There
is one thing certain, and that is, any fire-proof build-
ing, intended for storage purposes, should have the
iron construction, so far as is possible, a wrought-
iron one.
And it is desirable that even wrought
iron should be protected from the direct action of
flame by means of some non-conducting material.
Intense heat will destroy the strength of wrought
iron as well as that of cast, but it will stand an in-
finitely greater heat before it will yield. Plastered
timber, so long as the plaster remains upon it, cannot
be affected by ordinary fires, and is practically fire-
proof. Any means, therefore, by which a plaster
composition could be attached to exposed parts of
ironwork would be a great benefit in fire-proof ware-
house construction, and would make them in reality
what they are only in name. If columns could be
cased with a durable cement, leaving an air space
between the column and casing, it would be an abso-
lute impossibility for the iron column to become
heated to destruction. In fact, it may be said that
no iron building is fireproof simply because it is of
iron. The chances of fire are, of course, greatly
lessened, but it can be destroyed by fire, and until a
building can be made proof against destruction by
fire, as well as non-combustible, we are far from per-
fection in this class of buildings, at all events.

A

IRON MANUFACTURE ON LAKE
SUPERIOR.

LITTLE while ago, we, " American Journal of
Mining,"
," had occasion to speak of the inaugu-
ration of a new manufacturing enterprise in the
State of Missouri, with the object in view of utilizing
the deposits of zinc ores so abundant in that locality.
It is now our opportunity to speak of another in-
dustry that has been established lately, and which,
if we are not very much mistaken in our impressions,
will soon become one of the largest industrial
interests of the north-west. We allude to the
establishment of a large iron works at Marquette,
upon the southern shore of Lake Superior. Hitherto
it has been the custom to ship the iron ores taken
from the immense deposits in that section of the
country to Detroit, Erie, and Cleveland, from which
latter port large quantities of them are forwarded on
to Pittsburg, the great iron mart of the Continent.
The time seems now, however, to have arrived
when, upon economical grounds, it is possible to do
away, in part, at least, with this expensive shipment
It has been shown that pig metal and
merchant iron can be manufactured at Marquette, in
the immediate neighbourhood of the ore deposits,
at a rate of cost much less than at Pittsburgh, the

of ores.

commercial centre of the iron interest.

The following statistics of comparative cost, clipped from one of our exchanges, gives, we should judge, a very fair estimate of the respective rates of production:

PIG METAL-PITTSBURG.

1 ton ore at 12dols.

2

coal at 4dols.

Flux

Incidentals.

Labour

Freight to Chicago.

11⁄2 ton ore at 5dols.

Total

MARQUETTE.

2

coal at Cdols. .

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Flux

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Dols. c. 18.00 8.00 1.00 3.00 1.00 7.00

38.00

7.00 12 00 1.00 3.00 1.00

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27 00

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an eminent success. Ores are at hand; coal can be
obtained at a slight rate of cost over and above the THE MECHANICS' MAGAZINE is sent post-free to subscribers
Pittsburgh price; labour is worth no more than at of £1 1s. 8d. yearly, or 10s. 10d. half-yearly payable in
the latter place; and then, again, the rapid develop-advance.
ment of the north-west and west will offer an ex- All literary communications should be addressed to the
tensive and ever increasing market for the sale of Editor of the MECHANICS' MAGAZINE. Letters relating to
their merchantable products. It is no matter of the advertising and publishing departments should be ad
surprise to us that such an enterprise should springtressed to the publisher, Mr. R. Smiles, MECHANICS' MAGA-
Office, 166, Fleet-street, London.
into existence; rather, it is a surprise, that instead
of only one, there are not a dozen furnaces ready
to enter upon this work of western iron manufacture,
But, again, if, as we believe, at no distant day,
the peat beds which lie in the immediate vicinity of
the ores can be brought into service in the production
of a first-class quality of iron, a new impulse will be
given to this new iron enterprise. They will be to
the iron beds of Superior what the coal fields of
Pennsylvania are to her deposits of ore. There
seems, indeed, in all this to be good grounds to hope
for the realization of the prediction that Marquette
is to be the Pittsburgh of the great north-west. We
shall watch with interest the development and
growth of their new industrial enterprise, and hope
that the anticipations of those who are immediately
connected with it will be fully met.
It certainly
marks an era in the history of the metallurgical
industry of the country, and, at a later day, its
influence may become so extended as to bear no
longer a sectional, bit rather a national character.
As such, it is no less our duty than pleasure to
record what we hear in regard to its successful
inauguration.

Correspondence.

A MANUFACTORY OF WATCH GLASSES
TO THE EDITOR OF THE "MECHANICS' MAGAZINE."
SIR,-The description inserted in your last num-
ber, from the "Horological Journal," of the processes
followed out at Sarrebourg, gives a very poor notion
of modern practice in this manufacture; in fact, it pre-
sents the appearance of having been written at the
commencement of the present century, and does not
even allude to the commercial name that flat watch
glasses have always borne, "Verre a Lunette." It is
true that the common convex glass is cut from a
blown globe, but not in the rude manner as described,
by breaking and chipping, a process that would
render them very expensive, as only one glass could
be obtained from each large globe. The cutting out
is performed by means of the glazier's diamond, the
globe being placed in the cup chuck of a vertical
fathe, and is started out with a few taps of the handle
of the diamond. The globe is then turned about in
the chuck, and as many glasses of various sizes are
cut out as the spherical superfices will hold, but
when the diamond is applied to flat sheet glass, the
circular piece cannot be started without breaking the
outer portion. There is no pattern or measurement
required, for the only difficulty with a practised
artizan is not to produce the glasses of exactly the
same size. The convex glass thus produced is
usually ground on a flat stone to a sharp edge, which
is slightly rounded off with a smooth file.

Advertisements are inserted in the MECHANICS' MAGAZINE, at the rate of 6d. per line, or 5d. per line for 13 insertions, or 4d. per line for 26 insertions. Each line consists of about 10 words. Woodcuts are charged at the same rate as type Special arrangements made for large advertise

ments.

RECEIVED.-J. T.-M. B.-T. C.-M. P. S.-S. E.-W. H. and Co.-W. R.-D. P. S.-R. L.-S. T.-G. W. H.-E. W. A. B.-E. H. B.-C. E.-G. F.-W. T. F.-R. T.-J. C.G. J. G.-W. B.-C. H.-R. D. N.-H. A.-T. W.-H. L.J. H. P.-B. H.-S. T. D.-R. M.-H. J.-E. T.-G. G.— R. T.

R. J.-H. and G.-W. P. N.-W. E.-J. C.-C. G.-W. H.

Meetings for the Jacek.

MON.-Society of Engineers.-Mr. Ewing Matheson on

The Accumulator Cotton Press," and Mr.
Baldwin Latham on "The Application of
Steam to the Cultivation of the Soil," at
7.30 p.m. After the meeting, there will be a
Ballot for the Election of New Members.
Royal Institution.-General Monthly Meeting, at
2 p.m.
TUES.-The Institution of Civil Engineers.-Discussion
upon Mr. Wheeler's Paper on "The River
Witham and its Estuary," at 8 p.m.

WED.-Civil and Mechanical Engineers Society.-Mr. B.
Haughton on "The Tidal Wave in British
Waters," at 8 p.m.

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Habal, Military, and Gunnery Items.

SIR JOHN PAKINGTON has appointed Captaiu Brome, late Governor of the Military Prison at Gib raltar, to the Governorship of the Military Prison a Weedon, vacant by the death of Captain Boyle.

Government propose to give some reward of honour WE are glad to learn that there is a report that the his chilled shot-have been and are productive of to Major Palliser, whose inventions-particularly enormous saving to the country, while they add greatly to the efficiency of its armaments.

THE "Friend of China" states that an accident occurred on the night of the 3rd October, by which Mr. Harris, the paymaster of Her Majesty's ship "Rodney," lost his life. He, in company with two other officers, were in a boat, which, getting foul of some fishing stakes, capsized. Fortunately, all his companions were saved, though Lieutenant Farquharson, of the " Rinaldo," had a most narrow escape.

THE Contract for the construction of the engines and machinery for the ironclad turret ship "Glatton," has been given by the Admiralty to Messrs. Laird Brothers, Birkenhead. The engines and machinery for the ironclad broadside ship "Sultan," under construction at Chatham, will be manufactured by Messrs. John Penn and Sons, the makers of the engines for the "Hercules."

THE Hercules'

The flat or lunette glass is not cut out from a globe, but from a bottle blown nearly the size and shape of an old-fashioned wine-glass without the foot, and not cut open at the top, each bottle forming only one lunette, which is cut from the body by grinding with emery and water in a thin conical chuck of a swift horizontal lathe. The copper cup raw edge is again ground with emery in the same or a similar copper cone, and polished as usual with putty powder. Flat sheet glass is curved in the muffle furnace, as described by Gustave Maurice, has been placed in the great only for large clock faces. The whole of the above "Minotaur" dock in Portsmouth Dockyard, to operations are carried on by an expert workman cleanse and repaint her hull below the water line, in with astonishing rapidity. Lunette glasses were in readiness for her trials. Her bottom was found to use long before the year 1820; for, being in London be covered with an extraordinary thickness of barin 1822, I broke the glass of a watch purchased innacle and other marine incrustations, fully accountDifference on pig metal in favour of Marquette Geneva, and, on applying to a watchmaker, he said ing for her speed not exceeding twelve knots under that he could get the lunette glass replaced, but that 59 revolutions of her engines during her recent pasit would be dear-some four or five shillings; if, how-sage round to Spithead from the Nore. ever, I would take the trouble to call at a certain address in Wardour-street, Oxford-street, I might it put in for much less. I found the grinder at get work in a garret, and he put in one for half-a-crown in every respect the same as the original. Every one knows how easily and cheaply they are now to be obtained. I believe the use of the glazier's diamond is now superseded by a pointed blast of heated air, as glass will separate accurately in the travel of the hot blast, the globe being carried round in the cup 3 00 chuck of a slow motion vertical lathe as before.-I am, Sir, yours, &c.,

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15.00
8.00

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30 62

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15.00

58 62
9 18

Difference in favour of Marquette Basing their calculations upon estimates of the above character, a company formed some two years ago have erected a blast furnace of thirty tons capacity, together with a rolling mill, puddling furnace, and all the appurtenances necessary to the manufacture of merchantable iron. The rolling mill, we understand, is already in successful operation,

and the furnace is soon to be set in blast.

We see

no reason why this enterprise, begun, most certainly, under very favourable auspices, may not meet with

Reading, November 30.

HENRY W. REVELEY.

IT is well to mention, previous to the present Board of Admiralty quitting office, that in the naval estimates for 1868-9 a sum of £6,000 was granted by the House of Commons for increasing the pay of the senior branches of the Royal Navy, not one shilling of which, if we (the "Times") are informed correctly, has been appropriated to its intended purpose. During the past year only two promotions have been made from the rank of engineer to that of chief engineer, and in both these instances the promotion was given for special service. It must be presumed that attention only requires to be called to such matters to insure an immediate and efficient course of action being taken for their removal.

A STEP in the right direction has been made in ACCORDING to a report published by the Council providing for the seamen and marines on the Cape of State of Ticino, the Hospice of Saint Gothard, the Station a rendezvous and means of recreation more most frequented in Switzerland, received and enter- in accordance with the ideas of the day than is tained 8,574 travellers during the year ending Octo-afforded by the public-house and other places that ber 1, 1868. It gave medical attention to 47 persons have hitherto been open for their reception. The partly ill and partly frozen; 24,791 rations of bread; Lords of the Admiralty have authorized the converand many articles of clothing, especially shoes and sion of an old store, at Simon's Bay, into apartments socks, were distributed. The total expenditure was for the meeting of those serving in the fleet on the 9,057f. station and in transit, the lower portion for the sea

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