Kfa 



0$ THE BASALTIC COUNTRY IN IRELAND- M*>* • 



sound either to jthc front, middle, or last benches, -A3 

 thought best, this shown at 1, 2, 3. The two latter, 

 where altered from the former, by dotted coves. The 

 fronts to the boxes should present reflecting curves, to 

 throw their sound within the fourth region of the pit. 



Fig. 3 is a hind view, showing the proper curye of the 

 roof in this position, where the only object is tp keep the 

 diverging rays of sound parallel after reflection, and clear 

 of the sides of the boxes. 



I think it would not be particularly expensive to have Cast iron beams 

 tjie whole beam and pillar work of the theatre of cast iron ; aild pillars * 

 and likewise to make the elliptical part capable of being 

 completely cut off from any fire in the other part of the 

 building, by a jointed sheet iron curtain, to close up the 

 stage every night after performance, or in case of fire, 

 during tfre play hours. The name of th'13 would be very 

 attractive. 



To prevent the bad efTect of squeezing from sudden Doors to open 

 alarms, no door about a theatre should open inwards, and outwards# , 

 the outlets should be as large as possible, and some extra 

 ones easily opened if necessary : a good reservoir of water, 

 and an engine pr two on the spot, are precautions too ob- 

 vious to need an observation. 



I have the honour to remain, Sir, 



Your obedient servant, 



GEQ. CAYLEY, 



II. 



A Letter on the Alterations, that have taken place in the 

 Structure of Rocks, on the Surface of the Basaltic Coun- 

 try in the Cotmties of Derry and Antrim, Addressed to 

 Humphry Davy, Esq., Sec. li. S. by William 

 Kichardso.n, D. D. 



(Concluded from p. 175. ) 

 Inquiry into the Formation of our perpendicular Facades. 



T is natural, that the first great operation we proceed to Formation of 

 inves^gate should be the formation of our magnificent fa- the cliffs. 



jades, 



