PATENT OROPHOLITHE.

Nelson Examiner and New Zealand Chronicle, Volume II, Issue 90, 25 November 1843, Page 359

PATENT OROPHOLITHE.

We are indebted to the New Zealand Gazette for the following description of the serviceable qualities of this new invention. We also learn from the same paper that a gentleman came out in the Ursula to work the patent in these colonies.

The patent oropholithe, as its name imports, is a material principally adapted to the covering of roofs, it is also used with much advantage as a substitute for oilcloth to cover floors, or as a lining to water-tanks. It was invented in France about sixteen years ago, where it has been extensively employed, under the patronage of the National Institute, on many public and private buildings. A patent was secured for making it in England and the colonies 6ome years ago, and in a space of time remarkably short, considering the novelty and simplicity of the invention, it excited the notice of most builders and architects, and more particularly of the Government, by whom it was immediately adopted as an efficient covering for the large roofs in the Dock and Victualling yards. It soon acquired the approbation of private individuals, in its several adaptations to roofs, walls, floors, water-tanks, and cisterns, in preference to lead, zinc, tiles, or slate —in its durability and power of resisting the effects of atmospheric inclemencies, and the action of water — in its lightness, cheapness, and the immense saving of material, time, and labour; and its effects were its chief recommendations ; to these circumstances are to be attributed the patronage it has received.

Such properties could hardly fail to point it out to the eye of the intending colonist, as eminently adapted to the wants and purposes of building in a new colony. But there are objections to its exportation, which originate in the expense of securing, packing, carriage, freightage, and risk, besides other contingencies, which would at once destroy its most attractive feature to the colonist, viz., its cheapness.

With these considerations in view, a license has been purchased of the patentees in England to manufacture and sell the patent oropholithe in New Zealand, so that the colonists might procure it free of additional expense, and of every risk of loss or damage.

Its composition is extremely simple and the ingredients easily procured. A cement is formed of river or pit sand, whiting, and litharge, finely sifted and mixed with linseed oil, the proportions of litharge and oil being extremely small. This cement is laid on one or both sides of a coarse canvass, forming, when dry, a sheet threeeighths of an inch thick, and about 32 feet square in extent. The sheets are suspended till dry, and when required for use are cut to a uniform size on a cutting table constructed for this purpurpose; they are then carried flat on a board to the spot where they are required, and laid with a lap or close joint to the roof, boarding, wall, or cistern, the joints and heads of nails being carefully stopped and covered with the cement. This operation requires much less time and trouble than the most ordinary roofing now in use. The durability of the oropholithe is a consequence of the chemical combination of its component materials, which renders it so hard that steel may be ground on it without producing injury to its surface. The cement, however, is by no means a novel invention, being, in fact, a modification of Hamelein's cement (well known in the arts), both being composed of materials insoluble in water; and though the oropholithe is more durable and adhesive than the other cement, its place might, under circumstances, be substituted by it. The great novelty, as well as the utility of this invention, consists in laying the cement on canvass ; without which, it could never have been applied to the covering of roofs or floors as a substitute for oilcloth.

It may be objected that, although the cement resists the action of the atmosphere and of water, the canvass possesses by no means these properties, and thus the bond which unites the cement in a layer, and renders it available for the purposes of building, being destroyed in a short time by these external agents, the cement would collapse; and, consequently, as an .external covering becomes useless. It may be answered in the first place that, so long as the boarding to which the oropholithe is nailed maintains its position, even were it possible for the canvass bond to be destroyed, so long will the cement retain its place, by the mere power of cohesion, which it possesses in an eminent degree. But it is absolutely impossible that the canvass should be prematurely destroyed, unless the cement ceases to cover it. For we all know that the canvass which has been found wrapt round the mummies of Egypt, after the lapse of many centuries, owes its preservation chiefly to the absence of its contact with atmospheric air. It follows, therefore, that if the sides and edges of the canvass which forms the bond of this cement be protected by a coating of cement impenetrable to the action of the atmosphere, its duration must equal that of the cement itself, which certainly rivals, and, in many instances, surpasses, that of lead.

As an instance of this for the purpose of cisterns, it may suffice to state an experiment made by the Oropholithe Company. In the courtyard of their .manufactory in London, an outhouse of framed timber was constructed, and covered externally with oropholithe; a cistern on the summit, fourteen feet square by two feet deep, was lined with oropholithe, composed of some waste pieces joined together, for the purpose of showing the efficiency and tightness of its joints. It was filled with water, and has remained for two years exposed and uncovered, having been frozen over several times, without

the slightest appearance of leakage or damage of any description arising either from the most powerful sun or intense frost. It is equally well adapttd as a substitute for oilcloth, which it far excels in durability and beauty of appearance, as it is capable of receiving the brightest colours, which forms part of the material itself, and consequently are equally durable, and can be made to any pattern, however complicated. It effectually excludes the damp from the floors, and for this purpose a great quantity of it of a tessellated pattern has been laid in the vestibules and offices of Buckingham Palace, in lieu of the oilcloth which was originally employed, and generally renewed every nine months; whereas the oropholithe, though laid down two years since and subject to great wear and tear, remains as good as ever. It has been employed in underground kitchens and warehouses for the same purpose, and with the same excellent result. Thus it suggests itself as an invaluable material to storekeepers in a colony, both as an external and internal covering. Mr. Loudon, in the Gardeners' Magazine, has recommended it for garden walks, and it seems to answer this as well as every other purpose. Another property it possesses is that, though it resists friction, and will grind- the hardest knife to a stump, it is cut without much difficulty, thus affording every facility to the workman.

We have stated that, as an external covering, its price is inferior to that of any other. The average of the commonest slating in England is thirty-five shillings the square of 100 superficial feet; such slating requires a strong boarded roof to be raised to a pitch certainly not less than an angle of 45°, and providing, after all, * an inefficient covering, constantly requiring extensive repairs, at an infinite expense and waste of time and labour. The oropholithe;; js, in England, laid on roofs of any pitch, or perfectly flat, of much lighter construction, at something less than thirty-five shillings the square of 100 superficial feet, providing at the same time a covering equal to lead; while the company makes itself liable for any repairs it may require during the 6pace of five years, and in few instances has it been necessary for the workmen to go over their work even on the. large and exposed roofs of the dock and victualling yards, but where such has occurred, the facility with which a seam not properly cemented may be stopped has rendered it a matter of inconsiderable trouble.

The price of the material itself is low, but it is the saving of roofing which it effects that renders it an object of the greatest consideration. This immense saving is effected principally by the lightness of the timbers required in a roof covered with orotholithe, and the absence of any necessity to raise the pitch of the roof beyond the smallest angle required to carry off the rain water, which has the double effect of diminishing the quantities of the roof timbers, and also of the external covering, whatever that may be. In this we refer to roofs not covered with metal, as they of course can be laid to any pitch j but it must be remembered that such a roof, whether lead or zinc, would cost more than double one formed of oropholithe. In order to illustrate what we have advanced with regard to the lightness of construction in an oropholithe roof, we may state that the slates average in weight 46cwt. to the thqasand, which gives an average of between 14cwt. and 15cwt. to the square of 100 superficial feet, requiring from 275 to 325 slates. A plane tile weighs two pounds and a-quarter, and a square requiring an average of 700 will weigh upwards of 15 cwt. The average weight of pantiles is silbs. each, and a square requiring 180 pantiles would weigh 9221b5. Ridge tiles weigh four pounds and ahalf each, and the weight of a square is somewhat more than 900lbs. Now five sheets of oropholithe cover a space of more than 120 feet superficial, and their weight is something less 1451b5. ; this immense difference, as every one must perceive, allows of a very great reduction in the strength of timber in a roof. In fact, almost all that is required in an oropholithe roof is, that the timbers be not too slight to withstand their own strain, and thick enough to allow of convenient framing. Nor must it be forgotten that this arrangement extends its effects to the walls of a building, accomplishing throughout the objects of economy; and as its quantity is easily calculated and the risk of breakage inconsiderable, there can be little danger of fraud or loss, and thus the builder as well as his employer will be equally secured from either.

An oropholithe roof, presenting .an uniform surface to the weather, at an inclination just sufficient to admit of the discharge of rain-water, presents greater powers of resistance; an instance of this occurred at Brighton, where it was laid on the roof of a house contiguous to one covered with lead, and during a heavy gale the lead was stripped off, the wind having lifted the flushing, while the oropholithe, being connected throughout bjpa close joint, remained intact. This circumstance was the cause of an immediate and extensive demand for it throughout the exposed parts of the town. The surface of the oropholithe being even, the beauty of its appearance is much enhanced, while its colour may be chosen to please the eye and taste of every individual. Little more need be. said of the properties of the oropholithe as a* building material. It will be sufficient to add that it has been invariably observed that neither vermin nor rats infest its vicinity.

Canine Sagacity. — Sergeant Wilde relates a story of a dog known to him, which was kept tied up, aa a precaution against hunting sheep. At night he slipped his head out of the collar, and, returning before dawn, put on. the collar again, in order to conceal bis nocturnal excursion.