to the Antarctic Tlegiom. 221 



which falls, and of the fits or intermittences of its fall, as correspond- 

 ing, or not, to great bursts of lightning, as also of the direction of 

 the wind, and the apparent progress of the storm with or against it*. 



9. Registers. 



The Register proposed by the Council may be comprised in two 

 skeleton forms, which have been supplied to the magnetical obser- 

 vatories and to the Expedition. 



They are each calculated for one month's observation. The first 

 form is for the insertion of observations as they are made in their 

 uncorrected state. It consists of 12 principal divisions, and is ruled 

 across for 31 days, and for the arithmetical convenience of casting 

 up the sums and means of the quantities inserted. At the bottom 

 of the sheet there is also a space provided for the hourly observatiojis 

 of the barometer and thermometers on the hoentyfirst day of th^e 

 month, which will be more particularly described after the explana- 

 tion of the principal divisions. 



The outside compartments, both on the left and right of the sheet, 

 are for the date of the month and the phases of the moon. 



The second compartment is for the height of the barometer, and 

 the temperature of the mercury for the four regular periods of ob- 

 servation. 



The third compartment is appropriated to the dew-point hygro- 

 meter, and contains also four columns for the four daily observations, 

 each of which is subdivided into three ; for the temperature of the 

 air, the dew-point, and the difference between the two. 



The fourth compartment is for the wet-bulb hygrometer, ai;d is 

 similarly divided and subdivided for the temperature of the dry- and 

 wet-bulb thermometer, and for their differences. 



The fifth compartment is prepared for the maxima and minima of 

 temperature, and is divided into three. In the first division are to 

 be recorded the maxima and minima of thermometers carefully 

 placed in the shade and screened from radiation. In the second, the 

 maxima of a blackened thermometer exposed to the sun, and the 

 minima of a thermometer placed in a metallic mirror, and radiating 

 freely to the clear sky. The third is devoted to occasional obser- 

 vations of the actinometer under favourable circumstances. 



The sixth compartment is for the temperature of the surface-water 

 of the sea, or of any river in the immediate neighbourhood of the 

 observatory. 



The seventh compartment is prepared for observations upon the 

 direction and force of the wind at the four regular hours of registry. 

 In the left-hand column of each division is to be recorded the direc- 

 tion of the vane, and in the right-hand column the height of Lind's 

 gauge, in tenths of an inch of water. 



In the eighth compartment the amount of rain is to be registered 

 once in the day ; and in the ninth, the electrical state of the atmo- 



* On these subjects the Council especially recommend the attentive i>erusal 

 of Arago's Notice sur le Tonnerre, 



