[ 49* ] 
The Hygrofeope is a Whip-cord, prepared after 
the fame Manner as that of the Society’s in Edin- 
burgh j the Difference betwixt its greatefl and lead 
Length, by their Manner of Preparation, I found, to 
be Five Inches ; for which I made an Index Five 
Inches long, and divided it into ioo equal Parts, the 
Fil'd of which is the Hygrofcope’s greated Length. 
Thefe Indruments are conveniently placed on the 
Outfide of a N. E. Window, in a large fquare Box, 
about 3 Feet broad, 6 Feet high, and Feet deep; 
which is & conflru&ed, that neither the Sun nor 
Rain can have Accefs to the Indruments, and is at 
the fame time fufficiently perflated to fhew the Tem- 
perature of the Air, having a great Number of large 
Holes, regularly placed, and pafllng obliquely up- 
wards, in both Sides, and in the Front, with Weather- 
boards placed over each Range of Holes, fo as to 
hang over them obliquely downwards ; and has like- 
wife a large Window in the Front, which is open 
from Morning to Bed-time : The Shutters of the 
Window are in many Places perforated obliquely 
upwards, that the Air may have a free Circulation 
through the Box, when the Window is fhut at Night. 
In the Column Cali Facies , I have only taken 
Notice of the Sky’s Appearance from the Zenith to 
within about 30 Degrees of the Horizon. 
N. Nubes. ' Small Rain. £. Thunder. 
Op. Opaces. “ Greater Rain. And 
Ob.Obduttum . in Very great Rain. 
T. Tenues. 
The Charaders for Rain exprefs the Time in which 
it rained, according as they are placed in the Column. 
When in the upper Part, it rained in the Forenoon : 
In 
