NoTES REGARDING METEOROLOGICAL INSTRUMENTS. Xvil 
The direction of the wind is indicated in this volume by the number of the 
point of the compass, reckoning N = 0, H=8,S=16, W = 24, 
The anemometer is observed in the following manner: About 2™ before the 
observation hour the position of the index is observed, and the pressure shown is 
registered as the maximum pressure occurring since last observation hour; the 
index is then put back to zero, and from 7™ to 10™ afterwards the position to 
which it has again been carried is noted as the present pressure; the index is 
then set to zero, and a similar double reading made at the next observation 
hour. 
The instrument registers the force of the wind in pounds on the square foot 
of surface (see Introduction 1845-46, p. Ix.). 
STATE OF THE SKY. 
The extent of sky clouded is estimated ; the whole sky covered with clouds 
being noted as 10, and the complete absence of clouds as zero. 
NOTES REGARDING METEOROLOGICAL INSTRUMENTS. 
1847, March 28.—New silk put on wet-bulb thermometer. 
Oct. 29° 23".—New silk put on wet bulb. 
Dec. 10° 3".—Iron bars put into grate. 
» Dec. 104 5"—Anemometer repaired. 
1848, Nov. 224 23".—Cord of anemometer found broken at 22"; a new one 
put on, but the instrument not adjusted. 
1849, July 20% 23".—New silk put on wet-bulb thermometer. 
1850, Feb. 84 22".—Anemometer leaky, the water taken out, a new bottom 
put on, and a new piece of copper tube put to the under end; 9° 8", placed and 
filled with water. 
1850, Feb. 14°—New silk put on vane. 
April 184 5".—The index of maximum thermometer is adhering to the 
” 
” 
2? 
mercury. 
DESCRIPTION OF THE TABLES OF THE OBSERVATIONS. 
Daily Observations of Magnetometers, 1847 to 1855 (pp. 1-47). 
The headings contain the Gottingen mean solar time, astronomically reckoned, 
of the observations of the declination magnetometer. Gottingen time is 49™ 50° 
in advance of Makerstoun time. The first column gives the civil day ; the second 
column gives the absolute westerly declination in degrees, minutes, and decimals 
of a minute, deduced as already described. 
The third column contains the observations of the bifilar magnetometer in 
