DESCRIPTION OF THE TABLES. Ixi 
100. A copper stove occupied the position S in the plan (Plate I.), and was 
lighted every day from January | till March 15, 1843, with one exception, namely, 
on January 23. It was only lighted three times again in 1843, namely, on Octo- 
ber 19, November 25, and December 21, as it tended to increase the diurnal range 
of temperature, and to create aérial currents within the Observatory. 
A small brick building was erected 24 yards to the east of the Observatory, 
which was occupied after March 16 as a computing room. It was determined that 
the bricks at that distance had no effect on the reading of the declinometer. 
= 
a 
§ 15. DESCRIPTION OF THE TABLES OF OBSERVATIONS. 
Daily Observations of Magnetometers, pages 1—28. 
101. The first column contains the Géttingen mean time, astronomical reckoning, 
of the observations of the declination magnetometer. Gdittingen time is 49™ 50° in 
advance of Makerstoun time. 
The second column gives the absolute westerly declination in degrees, minutes, 
‘and decimals, deduced as described, No. 23. 
The third column contains the observations of the bifilar magnetometer in scale 
divisions, corrected for temperature to 26° Fahr., see Nos. 39 and 45; increasing 
numbers indicate increasing force. The bifilar is observed 2™ after the declination. 
The fourth column contains the temperature of the bifilar magnet in degrees 
of Fahrenheit. 
The fifth column gives the readings of the balance magnetometer in microme- 
ter divisions, corrected for temperature to 26° Fahr., see No. 58 ; increasing num- 
bers indicate increasing force. The balance is observed 3™ after the declination. 
The sixth column contains the temperature of the balance needle in degrees of 
Fahrenheit. 
102. At the foot of each page are given the declinometer torsion-circle readings 
for the torsion eliminated. A comparison of any one reading with the previous read- 
_ ing will give the number of degrees of torsion introduced between the two periods ; 
10° of torsion introduces an error into the observations of 0’-9 ; references are made 
to footnotes, which at times indicate the cause that has produced the torsion, and 
' the period that it may have existed. The value, &, of one scale division of the 
bifilar magnetometer, the whole horizontal force at Makerstoun being unity, is also 
given, together with the approximate value, k, of one micrometer division of the 
balance magnetometer, the whole vertical force being unity, obtained as in No. 55. 
The value used in the abstracts differs considerably, and is k = 0-000009. 
The obseryer’s initial will be found at the same date of the meteorological ob- 
servations. 
MAG. AND MET. oss. 1843. q 
