184 Ohfevjatlons on the conJlruBion of Gates, ^^^T 



fheet iron efcutcLeons, like thofe at I, the faflening being com- 

 pleted with the catch H, having a button in the place of the ring. 



A model 01 this gate is fent w ith the plate, and may be feen at 

 the Ihop of Mr Courtabie, Publillier of the Magazine. 



A gate fufpended in the manner defcribed cannot be left open, 

 (exceptiiig in high winds) but will (hut of itfelf, tho'Viot with an 

 uniformly accelerated motion, as u:)igbt be fuppofed, its velocity 

 being rr.ther incrtjafed as it pafle^ the middL- parts of its fem.icir- 

 cular courfe. and retarded igain as it approaches its line of reft *. 



The cffecls of A'ind cannot l)e countei acted in gates by any good 

 conllrudion of the hinges j for, were a velocity given to a gate's 

 fall c-qu^l to the refinance of fo powe ful an agent, the gate would 

 foon Wi^nt repair, from the conftaut violence of its fhutting, and 

 be fo much the heavier in the hand of a horfeman : add to which, 

 that when a ftrong wind blew in the fame direftion as that of 

 the gate's fall, no man on horieback would be able to withltand 

 its force ; and well conflrucled gates are moll liable to be afted 

 upon by wind, from their wide extent of furface : but if paffengdrs 

 are fo carelefs as to leave gates open under fuch circumftances, 

 there will be one fatisfafli on remaining; that is, fo foon as the 

 wind ceafes, the hinges mull refume their property, and the gate 

 fallen itfelf. G is a common peg latch for the head of a gate with 

 a guard to render it fafer for cattle which might run a- 

 gainft it when the gate is open ; and this forms a very fecure faf- 

 tening, either with or \vithout the guard, when attaclied to the 

 catch H ; but it is thought very inconvenient for horlemen, and 

 particularly fo for thofe who are not accullomed to it. 

 H is the catch adapted to the larch G. 



I reprefents twufneet iron efcutcheons, and a pattern for a ftrong 



latch. 



* A pate nine feet long is made to rile fix inches at tlie head, from its Hnc of 

 refl to that of equilibrium, fnbicd to certain variations in the intermediate parts of 

 its motion, i'/z as the -rvz/r./ //;;.- of the angle formed by the gate, with its line of 

 reft, is to thr length of thic gate, which is made radius, fo will be the corrclpond- 

 ingrlfe of the head of the gate to three inches, at any given angle within the quad- 

 rant : and the rife of the head of the gate afterwards will l)e-as the co-fitse of any given 

 angle formed by the gate witli its line of equilibrium, in defcribing the complete- 

 ment of that angle, i^ tn the length of the gate, or radius, fo will be the t<irrefponding 

 rife of the head of the gate to the remaining 3 inches ; which o-fine of the 

 angle, formed hy the gate with the line oftquilibrium, is equal to the/?«f of the com. 

 plcmcntary angle, or angle of the gate's progrefs from a radius at rigr t angles to, 

 or cqui-difii'nt from the lines of reft and equilibrlxmi, as the gate approaches the 

 line of equilibrium in performing its fupplementary courfe. This might be bet- 

 ter 'xpluined by a diagram, hud not the plate been arranged more appropriately to 

 this publiv-ation ; and thofe who may be dtfirous of purfuing this fuhjed further, 

 1 muft refer tc a pamphlet which will fliortly We reprinted by Lackington and Co. 

 JL/ondon, with 6vc or fix quarto plates. 



