same vertical plane with the gate's line of fastening, which shall be also made its line of equilibrium; by attaching the proportionate extra length to the upper thimble instead of the lower one: this gate when fastened should be quite upright, but it will fall open to the right or left, and remain open by approaching its natural line of rest, which being thus reversed may be made in such cases to answer a very good purpose; particularly by the gate's continuing out of the way of carriages, until the person attending brings it upright again to its line of fastening.

Gates of an ornamental or fancy construction generally require strap hinges, and will sometimes be too heavy for the sudden check of the double catch Fig. 10: then the double hooks of the lower hinge Fig. 8 may be placed further asunder, which will add considerably to the fall of the gate; and there does not seem to be much use in a contrivance for preventing a heavy gate from being taken off the lower hinge, its weight being a sufficient security in that respect.

A notch, of a moderate depth and width, in a piece of iron makes a suitable catch for a gate of the last description, having sides gently to direct the latch up or down an inclined plane, so contrived as to admit of some vibration in the gate's swinging; which fastening is very common where the latch moves upwards: but I would recommend that the latch should move downwards, whereby it will be less liable to be out of order should the gate sink at the head; and the fittest form of a latch in such case, is like the lower or horizontal part of the jointed latch Fig. 4, and made to rest upon one of the bars of the gate, with the semi-circular handle also, but without any upright wire as at Fig. 4; avoiding every VOL. II.-SECOND SERIES.

I

kind

kind of spring fastenings when they are to be constantly exposed to the weather. But there does not appear to be any objection to the latch with the upright wire as at Fig. 4, provided care is taken not to make the back part or handle of it too heavy; because in this fastening the catch is solid, and the fore part of the latch must sink and give place to the catch, while in the other instances the catches give way to the latches, as the gates fall and fasten themselves.

Having endeavoured to adapt these pages as well for the intelligent artificer, as for the scientifick reader; it may not be improper to add, that I have no sort of interest in the bargain which I have made for the publick with the blacksmith and carpenter, who have contrived tools for the expediting and improving of their work; which with the advantage of executing several orders together, induce them to hope for a continuance of the encouragement they have already experienced; that their goods can no where be matched at the same price*,

I shall

* Samuel Lawrence, Blacksmith, and William Bucknall, Joiner, Shifual, Shropshire, will pay due attention to letters of orders postpaid, with ready money, at the under-mentioned prices; and gates for opening one way, as well as common iron-work, will be made all righthanded, like Figs. 2 and 4, unless the contrary be specified in the order:

Wicket of any common dimensions to the pattern of Fig. 4, 1 2 Q

Strap

I shall conclude this article in the words of my pamphlet *, with the wish equally to avoid intruding an apology unnecessarily, as to appear insensible to the defects of this production: I must assure my readers, that either by their pointing out errors into which I have fallen, or by suggesting improvements that might add to, or even supersede these hints, I should consider myself most particularly obliged.

Hatton Grange,

16th Oct. 1802.

SCALE OF PLATE III.

Fig. 4, half an inch to a foot.

Figs. 5, 6, 7, 9, 10, and 11, an inch to a foot.

Strap-hinges and heavy iron-work adapted to any orna

mental gates (an exact out-lined drawing of the same being furnished) 8d. per lb.

£. s. a.

Box, packing, and booking for any order not exceeding 12s. 0 1 0 And for every additional shilling,

0 0 1

Shifnal is only six miles from the river Severn, and twelve from the Staffordshire canal, by which means gates, &c. may be forwarded at a small expence of carriage to any part of the United Kingdom.

* Printed for Lackington, Allen, and Co. London, price 2s.

Method of rendering Whitewash made with Lime durable; also a Method of making a Composition to be used as a Substitute for drying Oils. By General LEVAVASSEUr.

From the ANNALES DES ARTS ET MANUFACTURES.

I AM enabled to certify the efficacy of marine salt in

fixing whitewash made of lime. In the year 1795, when I was director of the naval artillery at the port of Toulon, I was commissioned to ascertain the utility of a method proposed by the master painter of that port, M. Maquilan, for whitewashing ships between decks, and likewise their holds, in a durable manner, by means of lime. Our report was in favour of this process, which consists in saturating the water in which the lime is slaked with muriate of soda. The whitewash produced by it is very permanent, does not crack, nor come off upon one's hands or clothes. The experiment was made only on wood. It appears, from M. St. Bernard's account, that it succeeded equally well on walls. The same worthy and learned man says, that this is not the case with M. Cadet de Vaux's whitewash, prepared with milk * which many persons of my acquaintance, who have used it, have found not to answer, as humidity affects that composition very much.

I find in my notes the composition of a liquid mixture, invented in 1795 by the same Maquilan, as a substitute for drying oils, of which the port of Toulon was actually destitute at that period. As I was an eye-witness of the preparation and application of this mixture, I can answer for its success.

* Published in the 15th vol. of the first series of this work page 411.

Take

Take 16 lbs. of spirit of turpentine and 3 lbs. of tallow. First melt the tallow by itself; take the vessel from the fire, pour into it the spirit of turpentine, which must previously be warmed: put the vessel again on the fire, and, after boiling half an hour, proceed to a secondoperation.

Take 12 lbs. of spirit of turpentine and 12 lbs. of dry pitch and tar altogether into the second vessel, and set it on the fire. When the pitch and tar are dissolved, pour the solution into a third vessel together with the first solution of tallow and spirit of turpentine, which must be kept hot for that purpose: set the mixture again on the fire, and boil it for a quarter of an hour; this mixture is then used to grind the colours on marble, for a future supply.

A second solution of spirits and dry pitch and tar is prepared, and put by to dilute the colours ground and prepared as above, when they are wanted for use. Colours thus prepared, are equally applicable for wood or cloth.

Colours mixed up with this composition dry in less chan four hours in the shade; but if exposed to the sun, they the following day discover a little viscosity, and stick to the fingers. However, this is only a temporary defect, for in four or five days the composition becomes so dry that the sun cannot afterwards soften it.

White-lead and minium cannot be used with this composition, because they become hard the moment you attempt to dilute them; this effect is not produced with ochres, nor with lamp-black.

I need not say that I do not communicate this as an economical process, but there may be occasions when the oils generally employed in painting cannot be procured; and it is then fortunate to have a substitute at hand.