242 PL AN FOR AN IMPROVED THEATRE. 



Theatres are The ancients bestowed grt&t pains upon their theatres, 



orUnce "*" anc * ^^ are certa,n 'y nn object of considerable importance 

 in society. I conceive there can be no difficulty in blending 



Convenience the beautiful with the useful in the construction of these 

 should be uni- ..... .„ . . . , . , , . . , . 



ted with beauty buildings, if they do not indeed go so much hand m hand, 



in them. as almost to be inseparable. You will perceive, that the 



The principle plan I allude to is constructed upon the principle of apply- 

 stnene^hen the m % a ^ tne soun ^» tnat can be caught, by the reflecting sur- 

 ▼oice by re- faces of the building, to those parts only of the theatre 

 flecte sound, w h ere t ], e direct voice of the actor may prove too weak to 

 be heard distinctly. There should be a note inserted to 

 this effect in some part of the letter, viz. that as no simi- 

 lar sounds uttered in succession to each other can be heard 

 separately by the finest ear, when the interval of time be- 

 No echo would twecn each does not exceed T V of a second; therefore, no 

 in certain li- " reflected portion of a sound that arrives at the ear within 

 mits. less than T V of a second after the direct pulse will make a 



separate impression, or echo, but will add to the strength 

 of the former impression. Hence, as sound travels about 

 1142 feet per second, unless the difference between the 

 whole distance travelled over by the reflected pulse and that 

 of the direct pulse be greater than 214 feet, no echo will 

 be perceived. Tn the plan of the theatre sent, the greatest 

 difference of this sort only amounts to 69 feet; therefore, 

 even in this instance, about one half of the influence of the 

 reflected pulse would be exerted in adding to the intensity 

 of the sensation of the direct pulse, and about one half in 

 prolonging a nearly similar impression. 



I must apologize for writing to you in so slovenly a man- 

 ner: I am much hurried, being just setting off on a jour- 

 ney, and I coneeive, that, unless these hints can appear in 

 your next number, they will be forgotten before another 

 theatre requires planning. In the mean time I beg to 

 thank you for much pleasure and information conveyed to 

 mc by your Journal. 



I have the honour to remain, Sir, 



Your obedient servant, 



GEO. CAYLEY. 



To 



