ON IlLUMIN ATIOX. 03 



tbe glass prcsent'rg to the descending rays surfaces less ia- 

 clined, more of the rays enter the f2;l'as8, and passing through it 

 afterwards in various directions, light is diffused in all the parts 

 of the room. And i^ is not solely for windows which look 

 into small courts that It is useful to employ roughened glass; 

 it may be used with much advantage in all cases Where win- 

 dows look against a high -vvall, at a small distance, and 

 especially if the wall be of a dark colour. But to return to 

 my subject. 



Without enlarging farther at this time on the construction Account of th« 

 of shavles to b€ used for masking and softening the too dazzling i^^^P- 

 flame of lamps, I shall give an account of the new lamp'whicli 

 J have lately caused to be constructed, and which I have tKe 

 ' honour of presenting to this learned society. 



This lamp, which is destined to be suspended in the middle 

 of a room, was particularly intended to light a dining-room, 

 but it may likewise serve to light a drawing-room, or a billiard- 

 table. The following are the details of its construction^:^ — 



A hollow hoop of tin, painted white, 12/^ English inches 

 in diameter within, 16" inches in diameter without, and -j% of 

 an inch deep, suspended in a horizontal position, serves as a 

 reservoir for the oil. In the centre of this circular reservoir there 

 arc three cylinders, or beaks, which inclose three circular wicks 

 of the usual form and size. These three vertical cylinders, 

 which touch each other, are soldered together, and connected 

 with the reservoir by means of three oblique tubes ^- of an 

 inch square, thiough which the oil flows to the wicks from 

 the reservoir. 



In order to catch the oil which occasionally drops from 

 these three cylinders, there is a cup, made of tin 41 inches in 

 diameter above at its opening, and 1 inch in depth in the 

 middle, which is placed at the distance of ^;|^ of an inch under 

 the lower ends of tl;e three cylinders. 



Each of these cylinders is furnished with a chimney, or tube 

 of glass, and they may be lighted either all three together, or 

 two, or one only, according to the quantity of light that is 

 wanted. 



This lamp is suspended by means of a hoop of brass, o^ilt, 

 U>,\ inches in diameter and 1| inch wide, havin>y a little 

 horiiontul ])roJ5Ction at its. lower cdn;e, internally, oa which 



VoL.XLV.— May, 1806. F ' the 



