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pursuits are now very different to those of the period referred to, I cannot but feel interested in a matter to which I then devoted much time and attention, and am, therefore, desirous to contribute the information I possess as to the merits of this case. Scansea, October 16, 1944.
Lond. Min. Journ.
Description of the Roof of the New Houses of Parliament. From
Weale's Quarterly Papers on Engineering. Of the superiority of iron over wood in the construction of roofs for buildings, the architects of the present day are becoming fully convinced, and the splendid example now set before them by Charles Barry, Esq., should at least induce all who have hitherto been indifferent to the advantages of this material in the essential qualifications of lightness, strength, durability, and safety, in cases of fire, to examine the subject with all the attention it deserves, and the result may be looked for in the more rapid progress of the substitution of iron for wood in constructing the principals of roofs, especially when of large span. Not to the roofs only, but to flooring joists, or girders, the metal material is happily adaptable also, wherever resistance to fire, and great strength, with small section, are primary objects in their construction. Of these valuable properties, the architect of this edifice has wisely and very fully availed himself, and he has, moreover, been, by this selection, enabled to offer facilities for carrying into complete effect the most complicated details of construction in flues, &c., required for the proposed system of ventilation for the extensive pile of building under his care.
But beyond the use of iron in forming the principals of his roofs, Mr. Barry has ventured to a further step, of which those unacquainted with the experience that he is cognizant of might not fully understand the wisdom, but which is thoroughly approved by all practical and scientific persons who have examined the subject minutely. We refer to the coverings of the roofs with cast-iron plates of a thin section, and galvanized by a process now admitted to present the best
a yet discovered means of protecting iron work exposed to the air and weather from their otherwise injurious effects.
Upon the many substantial advantages thus attained, we are induced to state briefly the impressions we have received from an attentive examination, we might say, most interesting study, of the roofs delineated and detailed in the eight accompanying plates. The cast-iron plates being cast of sufficient size to span the distance between each adjoining pair of principals, dispense with the necessity for any kind of boarding whatever, thus saving not only a great expense, but also diminishing the chances of damage by fire, which would, by destroying this boarding, leave the slates without sufficient support, thus making the whole roof liable to be broken in by their derangement; or, in the case of lead covering, the fire from the boarding communicated to the lead, would speedily reduce it to a liquid state, and create the most disastrous, or fatal, consequences. Again the cast-iron plates allow the formation of ornamental rolls on the
exterior, and parallel with the rafters, at the same time having vertical joints beneath these rolls, which, together with the horizontal joints, are so contrived as to be perfectly impervious to the admission of water. The architect being thus enabled to communicate an architectural character to the very roof, which cannot fail to be highly esteemed when seen in connexion with the striking features of the masonry below, when the edifice is completed. And these rolls, it must be remembered, which, in slate covering, would be impracticable, and in lead liable to considerable distortion and injury, are, when formed in iron, and cast as parts of the plates themselves, not liable to injury by any ordinary means, or circumstances, and will always retain their form, position, and imperviousness to wet and weather. To whatever purpose the spaces, or rooms, within the roofs may be applied,—and these spaces must, from the high pitch of the roofs, be very valuable for many purposes, it is evident that uniformity of temperature will be highly desirable; and this will be attained, it is believed, to a much greater degree by an iron covering than by one of lead, slate, or any other material. The corners of each plate being firmly secured by screws and snugs to the rafters on which they lie, a greater degree of lateral strength and stiffness is attained than can be had with any other kind of covering; in fact, the whole roof, principals, and covering become one piece of framework, well knit and secured together at all points by metal connexions, so that the longitudinal tie-rods, which are introduced at the intermediate points, are very much lighter than would otherwise have been advisable, and yet are abundantly sufficient for their purpose. Much greater facilities are likewise offered by this description of covering for the attachment of ornamental dormer windows, which the architect has introduced for the purpose of lighting the rooms within the roofs, and which could not, in any other material, have been so neatly, durably, or safely, constructed and attached to the covering. In point of durability merely, if lead be allowed a comparison with iron thus prepared and adopted, the latter must be pronounced the better material. As to weight, little or no difference can be stated; and regarding their comparative expense, it is believed, allowing fairly for all circumstances, the preference must be awarded to iron. Slate, of course, cannot sustain a comparison of durability, has little advantage in lightness, and not much in point of expense. But the many valuable peculiarities belonging to iron for the purposes required, and , at some of which peculiarities we have above glanced, should be held thoroughly decisive as to its employment in the erection of an edifice of which not only the architect in the present age, but the nation for many centuries, should be justified in feeling proud.
Civ. Eng. and Arch. Journ.
Railway Keys. By W. H. Barlow. The drawing of my hollow iron keys, which is given in your last number, is calculated to produce an erroneous impression as to one of the great advantages which they possess over modern keys. In your drawing you have shown the key as only fitting into the upper fin of the rail. In the enclosed sketch you will perceive that they fit into both the upper and lower fins, and this gives them a great advantage as joint keys, for the key being elastic the driving causes the contact with the rail to be very perfect, and the metal being hard no unevenness of the joint, or canting of the joint chair can take place, which is one of the great evils felt with wooden keys, for here the wood being comparatively soft and soon affected by abrasion, also the hold of the key on the rail being subject to great variation and shrinking of the wood in wet and dry weather, the joint chairs become canted, and the two ends of the rails out of level, which not only interferes with the comfort of traveling from the noise made in passing the joints, but produces unnecessary wear and tear in the engines and carriages, and increases the labor of repairing the road.
About two miles of the Midland Railway, that is four miles of single line, in the neighborhood of Rugby, which has been laid with these keys, show a remarkable difference in the steadiness of the road, and the quietness of the joints, as compared with the wood keys. It has been laid about six months, and the keys maintain their position, and hold on the rail as firmly as the first day they were put in.
The hollow iron keys require rather inore care and accuracy in laying the road than the wooden keys, but in other respects they are quite as easy to use, and drive readily into their places with the common keying hammer; however, I must not say too much in favor of my own invention; several engineers are now making trial of these keys, and we shall probably in a few months learn their opinion of them.
Resistance of Railway Trains. Mr. Scott Russell detailed a number of experiments on the Sheffield and Manchester Railway. For the purpose of these experiments it was necessary that the railway should present long and very steep gradients. The experiments were as follows:-1. Trains of carriages, empty, were put in motion at the summit of an inclined plane, at about 30 miles an hour, and were allowed to descend freely. 2. Trains of carriages, loaded, were tried in the same way. 3. The engine and tender were treated in the same way, being put to a ve.' locity of between 30 and 40 miles per hour, and allowed to descend freelythe whole length of the inclined plane without any train attached. 4. The engine and tender, with a train attached, were propelled to the
top of the inclined plane, and then allowed to descend freely
by gravity; by these means the following results were obtained:-1. The resistance to railway carriages at slow velocities does not exceed 8 pounds per ton. 2. The resistance to a light railway train of six carriages, at 23.6 miles an hour, was 19 pounds per ton. 3. The resistance to a loaded train of six carriages, at 30 miles an hour, was 19 pounds per ton. 4. The resistance to a light train of six carriages, at 28 miles an hour, was 22 pounds per ton. 5. The resistance to a loaded train of six carriages at 36 miles an hour, was 22 pounds per ton. 6. The resistance to a six-wheeled engine and tender, at 23.6 miles an hour, was 19 pounds per ton. 7. The resistance to a sixwheeled engine and tender, at 28.3 miles an hour, was 22 pounds per
8. The resistance to a train composed of six light carriages, with engine and tender, at 32 iniles an hour; was 22 pounds per ton. 9. The resistance to a train composed of nine loaded carriages, with engine and tender, at 36 miles an hour, was 22 pounds. Mr. Russell observed, that the subject was of considerable importance, inasmuch as the system adopted for laying down the gradients of new lines was of necessity regulated chiefly by the opinion of the engineer on the question of resistance. How much mechanical force is required to move a given weight of train, along a given gradient, at a given speed, was a question of which the solution was essential to sound engineering, but the profession had long felt that they were not in possession of sufficient data to determine this question.—Proc. Brit. Association.
List of American Patents which issued in June, 1844, with Re
marks and Exemplifications. By CHARLES M. KELLER, Ex
aminer of Patents. 1. For improvements in the Smut Machine, for Cleaning Grain;
Elisha W. Young, of Parkman, Ohio, and Thomas H. Wilson, of Harrisburg, Pennsylvania, June 5.
The rubbing of the grain is eflected in this machine, as in many others before it, by two horizontal disks, the under one attached to a shaft, and termed the runner, has its upper face armed with concentric rings of vertical pins, and the other, called the cover, has a series of rings (corresponding in number with the rings of pins on the runner,) which project from its face and have their inner sides ribbed, and a little inclined; the middle ring of the series projects downwards more than either of the others, and serves to arrest the grain more certainly. The spaces between the rings are filled with studs, or points. The grain is fed in through an eye in the centre of the cover, and is carried by centrifugal force beyond the periphery of the runner, and descends between it and the surrounding curb, where it
is met, and acted upon, by a current of air from a fan attached to the under face of the runner; thence it runs down inclined planes, which are perforated for the admission of air to the fan on the runner, and then into inclined spouts where it is acted upon by a current of air from another fan at the lower end of the shaft. The lower gud. geon of the shaft runs in a box, or step, the bottom of which is convex, and its centre is kept on the apex of this convex surface by a metal plate which fits the box, and which is provided with a hole for the gudgeon to pass through.
Claim.-“What we claim as our invention, is the cover having a series of concentric rings projecting therefrom, with studs between them, in the manner and for the purpose set forth. We also claim, in combination therewith, the runner constructed and arranged as described. We claim also the inclined planes having their lower sides punched with holes for admitting the air to the (upper) fan, in combination with the runner, as herein specified; and in combination with the spouts for directing the blast from the lower fan, and conducting off the grain, and separating the cheat, &c. therefrom. Lastly, we claim the step constructed as described.”
2. For an improvement in the Spring Bolt for Doors ; Albert Bing.
bam, Boston, Massachusetts, June 5.
This spring bolt, or mortise latch, can be thrown back, or opened, by either turning the knobs, or pushing them back. The spindle of the kuobs passes through a bridle, or loop, on the inner end of the bolt, and through an elongated hole, or slot, in the escutcheon plates, which are also provided with projections, or studs, ranged back of the centre, and one above the other in a vertical line; and the inner faces of the kuob sockets, which are concave, have a rib, or ledge, forward of their centre, and ranging vertically. When the knobs are turned, the upper, or lower, end of these ribs, or ledges, strike against the corresponding projections, or studs, on the escutcheon plates, and cause the knobs and the spindle to slide back in the elongated holes, or slots, of the escutcheon plates, and with them carry the bolt back; or the bolt can be retracted by simply pushing back the knobs.
Claim.—“I claim the ledge, or rib, (applied and affixed to the socket, or shank, of the knobs,) in combination with one or two studs, (inserted in, and projecting from, the door, or from an escutcheon plate, affixed to the door,) and an opening, slot, or passage, cut, or formed, through the door and escutcheon plate, for the shank of the knobs to move through horizontally; the whole being constructed, arranged, and operating substantially as described, and for the purpose of retracting the spring bolt either by turning, or sliding, the knob, or knobs, in the manner set forth.”
3. For an improvement in the Cooking Stove ; Isaac Straub, Cincin
nati, Ohio, June 5.
This is for a modification of that kind of cooking stoves in which the fire chamber is placed above the oven, and consists in so arrang