350 
Plan for an Improved Theatre . 
waste ; but, in m y opinion, argil would give very advan- 
tageous results : it retains, indeed, a pretty large quantity 
of oil, but, by means of a press, the last portions 
of the oil may be extracted from the argil almost entirely* 
No. 68. 
Plan for an improved Theatre . By Sir George Cay- 
ley, j Bart.* 
(With an engraving.) 
Brompton , September 25, 1808. 
Sir — Since the lamentable accident, that has so lately 
happened to the Covent Garden Theatre, the frequent 
occurrence of that event to my thoughts has led me to 
speculate upon the various improvements, that might be 
made in the construction of theatres. I have taken the 
liberty of enclosing you the following plan and hints, 
which I conceive to be worthy your attention, inasmuch 
as they state undoubted principles, which local conveni- 
ence may more or less permit to be put in practice, but 
without an attention to which no theatre can be pronounc- 
ed well constructed. The science of acoustics is perfect- 
ly well understood, and the enclosed rough sketch of the 
internal plan and elevation of a theatre is modified to the 
principles of that science, in conjunction with giving the 
greatest possible convenience of sight to the largest num- 
ber of people the space can contain. 
It is the property of an elliptical room, to collect all the 
sound uttered in one of its foci into the opposite focus by 
reflection ; hence, as the ellipsis is a very beautiful curve, 
and as it is only the parts of a theatre distant from the 
stage, that require the aid of reflected sound, I have adopt- 
ed this figure, as the ground plan, plate 10, fig. 1, will 
* Nicholson,, vol. 22, p. 243. 
