Desceiption of the Tables. Ixiii 



the order noted below. When the observation has been made more than 4™ too 

 late, the minute of observation is noted at the foot of. the page ; when less than 4" 

 too late, the true minute (for the declination observation) will be found in the first 

 column of the hourly and daily magnetical observations. The Gottingen mean time 

 is 49™ 50^ in advance of the Makerstoun time. The second column gives the height 

 of the barometer, corrected to 32° Fahr. (see No. 88). The barometer is generally 

 observed between the observations of the declination and bifilar magnetometers, that 

 is, about 70^ after the hour. 



The third and fourth columns give the observed readings of the dry and wet 

 bulb thermometers in degrees of Fahrenheit, uncorrected for scale errors (see No. 91), 

 and the fifth column gives the difference of the observed readings of the two thermo- 

 meters. The dry and wet bulb thermometers are generally read about 1^™ before 

 the hour. The sixth column contains the maximum pressure of wind on a square 

 foot of surface which has occurred since the previous observation (see No. 102) ; this 

 maximum is generally noted, and the index set back 2™ or 1™ before the hour. 



The seventh column contains the maximum pressure of wind on a square foot 

 of surface within from 8™ to 10™ at the time of observation, namely, from 2™ or 1™ 

 before the hour till 6™ or 9™ after the hour. 



The eighth column contains the direction of the wind read from the dial-plate 

 of the vane, and given in numbers of points of the compass, reckoning N = 0, E =8, 

 S = 16, W = 24. 



The ninth column gives the directions of motion of three strata of clouds in 

 numbers of points of the compass, namely, of scud, cirro-stratus, and cirrus ; thus, 

 June 13^ 20^ 1845, the surface wind, by the vane, blowing from 8 (E.), the scud 

 was moving from 4 (NE.), the cirro-cumulo-stratus was moving from 20 (SW.), and 

 the cirri were moving from 21 (SW by W.) (see No. 103). 



The tenth column contains the estimated extent of sky clouded, the whole hemi- 

 sphere covered being 10. 



The eleventh column contains the species of clouds observed, with other meteoro- 

 logical notes (see Nos. 103 and 104). 



The observer's initial will be found at the corresponding hour of hourly mag- 

 netical observations. 



112. Daily Meteorological Observations, 1845 and 1846, pages 274-276 and 

 412-413. 



The first column contains the civil day of observation, and the first column of 

 each division of columns thereafter contains the minimum temperature noted from the 

 self-registering thermometer about 10^ A.M. ; the second column contains the maxi- 

 mum temperature noted from the self-registering thermometer at 5^ p.m., the third 

 and fourth columns contain the minimum and maximum of radiation (see No. 92) ; 

 and the fifth column contains the amount of rain found at noon in the Observatory 



