406 Col, Beaufoy's Astronomical Observations, [June, 



Article II. 



Astronomical Observations, 1822. 

 By Col.Beaufoy, FRS. 



Bushey Heath, near Stanmore, 



Latitude 31o 37' 44-3" North. Longitude West in time 1' 20-93". 



April 30. Occultation of d Leonis by the? Immersion 15^ 08' 43-8" > o-, . , ^._„ 



moon .....{Emersion 16 06 00-3 J ^^^^"^ *^*- 



May 1. Occultation of uLeonis by the) g^^^^^j^^ ^0 30 gg ^ giderial time 



Article III. 



On a Clock with a Wooden Pendulum. By Col. Beaufoy, FRS. 



(To the Editor of the Annals oj Philosophy.) 



DEAR SIR, Bushey Heathy Stanmore, May 16, 1822. 



In the Annals of Philosophy for March, 1820, I was favoured 

 by the publication of a paper describing a clock with a wooden 

 pendulum, and its rate of going for 12 months ; and in the same 

 month of the following year, a similar table was inserted of the 

 daily rate for a like period. I have now the pleasure of sending 

 you a third year's register of the clock's diurnal variation. The 

 rod has hitherto remained in its natural state, but I purpose try- 

 ing the effect of covering it with varnish. If ohve oil be exposed 

 to the rays of the sun for a considerable length of time, it 

 becomes colourless, limpid, free from mucilage, and not easily 

 congealable. I have exposed two eight ounce phials, nearly filled, 

 with this oil, to the solar beams for one and two years, and con- 

 sequently can speak to the fact. The bottle should be opened 

 occasionally to allow the gas to escape, or the cork may be 

 expelled. Chronometer makers would find this mode useful o . 

 treating the oil they commonly use for clocks and watches. 

 I remain, aear Sir, truly yours, 



Mark Beaufoy. 



