311 
windows ; the next line (marked 2) is the level of the spring- 
ing of the second tier of windows ; the third the centre of the 
window termed "vesica piscis;" the fourth and fifth lines 
find the position of the strings ; the sixth the centre of the 
" wheel window the seventh the springing of the door- 
head, and so on; all the hnes being subdivisions of the 
normal or primary scale. By drawing vertical lines from 
those on the base, (being similar subdivisions of the scale,) 
and forming an isosceles triangle, whose base and height are 
equal to half the width of the building internally, and drawing 
lines parallel to the sides of this triangle, it will be found that 
these lines, by intersecting the vertical and horizontal lines, 
determine every important point in the elevation : this will be 
clearly seen by reference to the geometrical elevation, plate 2, 
No. 10. 
As the development of the true principles of Gothic archi- 
tecture is my sole object, I am anxious not to conceal the 
knowledge of any fact tending to prove that the principle, or 
an approach to it, has been acted upon by others. Caesar 
Csesariani endeavoured to exhibit the use of the equilateral 
triangle as applicable to the plan of Milan Cathedral. To 
myself the equilateral principle (upon the plan) is unsatisfac- 
tory, and for the following reason. In Milan Cathedral it is 
quite true that the equilateral triangles used have some slight 
reference to the extent of the building ; but the extreme intri- 
cacy of the lines is admitted, and precludes the practical appli- 
cation of Csesariani's theory. Again, Milan and many Conti- 
nental cathedrals have two aisles on each side of the nave, and 
as only one or two of our English cathedrals are so propor- 
tioned, this theory will not apply ; but observe, if you please, 
that the principle I advocate does apply to Milan equally with 
I York and other cathedrals. Rejecting the two outward aisles 
of Milan, the nave is four circles in length, and the projection 
of the transept half a circle ! My attention was first drawn 
