vill INTRODUCTION TO THE MAKERSTOUN OBSERVATIONS, 1847 To 1855. 
POSITION AND DESCRIPTION OF THE OBSERVATORY. 
The position and arrangements of the Observatory are described in the 
Makerstoun Magnetical and Meteorological Observations for 1845 and 1846,* 
(Introduction, p. ix.) 
SYSTEM OF OBSERVATION. 
During the year 1847, five observations were made daily, viz., at 20", 23°, 2", 
5", 8", Gottingen mean time. 
From January 1848 to February 1850, there were only two daily observa- 
tions, viz., at 23" and 5° Gottingen mean time; and from February 1850 till the 
end of 1855, there were four daily observations, viz., at 20", 23", 2%, and 5", Got- 
tingen mean time. 
From the beginning of the year 1851, meteorological observations made at — 
9 a.m., 9 P.M. (Greenwich time) have appeared regularly in the columns of the 
Kelso Mail newspaper. 
The only advantage here taken of these observations has been in the case of 
the calculated daily means of atmospheric temperature, and the maximum force 
of wind. 
DECLINOMETER. 
A detailed description of this instrument, and of the method of observing it, 
and also of reducing the scale readings to absolute declination, will be found in 
the Makerstoun Magnetical and Meteorological Observations for 1845 and 1846.* 
In August 1857, the adjustment of the declinometer was examined by Mr 
WetsH. The following are the results :— 
Arc-value of one division of the scale : ‘ = 06722. 
Zero point of the scale ‘ : = 257-25 divisions. 
Azimuth of the vertical wire of the ling telescope (A+ Z) = 25° 28' 7". 
These quantities being almost identical with the values given in the Intro- 
duction to the Observations for 1845-46, no change has been made in the co- 
efficients. 
At the same time, Mr WeEtsH determined that the arc-value of the scale 
divisions remained unaltered whether the scale was observed from the position of 
the transit theodolite, or from that of the fixed reading telescope, showing that 
the divided glass scale was truly in the focus of the lens with which it forms 
the collimator. 
It is found that the plane of detorsion of the suspending thread is apt to 
* Transactions of the Royal Society of Edinburgh, vol. xix. Part I. 

