On GOTHIC ARCHlTECrURE, 23 



Whoever pays any attention to Gothic archite(5lure, muft 

 obferve, in the upper part of moft windows, an ornament pro- 

 jedling from the bars, formed by two curved Unes meeting 

 in a point. It would be difficult to defcribe this form in words, 

 but it may be underftood eafily by figures 27, & 28. of Plate IV, 

 "which reprefent two contiguous windows of St Mary's, Bever- 

 ley ; in one of which the bars have been executed plain, and in^ 

 the other they have been ornamented in this manner. Figure 30. 

 is the window that lately ftood in the chapel of Holyroodhoufe 

 at Edinburgh, and figure 29. the fame general form executed 

 quite plain, as it fometimes occurs. As this ornament has not, 

 that I know of, been charadlerifed by any peculiar name, I fhall 

 apply to it that of cufp^ by which mathematicians denote a fi- 

 gure of the fame kind *. 



It was long before any fatisfa(5lory explanation of this form 

 occurred, though the frequency of its appearance, and the uni- 

 form manner in which it is introduced in all Gothic works, 

 ^eft little room to doubt that it had an origin, in common with 

 the more fubftantial forms of the ftyle. At laft a friend fug- 

 gefted to me, that it may have been borrowed from the appear- 

 ance affumed by the bark of the rods, when about to fall off, 

 in confequence of decay. With this view, having attended 

 particularly to branches in a fimilar fituation, I have met with 

 feveral fadls, which tend to confirm this conjecflure. The 

 dead branches of every kind of tree, after being expofed to 

 the weather during three or four years, throw off their bark, 

 which, immediately before it drops, curls into various fhapes, 



owing 



* Assemblages of thefecufps are fpoken of in the defcriptions of Gothic works, 

 by the naqmes of trefoil, quadrefoil, femi-trefoil, &c. but no proper word has been 

 ufed to defcribe the form, wherever it occurs, or however combined. This, 1 truft, 

 will fufficiently apologife for the liberty I have taken, of introducing a new term 

 into architecture. 



An application of the word cufp, as ufed by mathematicians, may be feen in Dr 

 Smith's Optics, Vol. I. p. 172. where he ufes it in defcribing the cauUics formed 

 by refledlion. 



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