to the Antarctic Regions. 223 



On either the scale of temperature or of pressure, occasional 

 comparisons may be made with results obtained at other stations, 

 which, if judiciously selected, cannot fail to prove of high interest 

 and importance. They should, however, be laid down in pencil, or 

 marked by a fainter line. 



At the bottom of the first skeleton form will be found a space pre- 

 pared for the 24' hourly observations of the twenty-first day of the 

 month, both in their uncorrected and their corrected state. It is 

 divided into four compartments for 6 hours each. The instruments 

 which can with most facility be observed in this manner, are the ba- 

 rometer with its attached thermometer, and the dry- and wet-bulb 

 thermometers ; and columns are appropriated to each of these. It 

 is desirable that the means of each 6 hours should be calculated, 

 and spaces have been provided accordingly for ttdp arithmetical 

 operations. 



In casting up the sums and calculating the means, care should be 

 taken in all cases to verify the results by repetition ; and the Coun- 

 cil recommend in every instance, before adding up the columns, 

 to look down each to see that no obvious error of entry (as of an 

 inch in the barometer, a very common error) may remain to vitiate 

 the mean result. The precaution should also be taken of counting 

 the days in each column, so as to make no mistake in the divisor. 



The skeleton forms will be interleaved with blank pages, to facili- 

 tate computations and comparisons, and to afford space for other 

 observations of atmospheric phenomena, which will perpetually pre- 

 sent themselves to those who make it their business or their pleasure 

 to watch the changes of the weather on a judicious plan. The 

 Council, indeed, wish it to be understood, that, in the suggestions 

 which they have offered, they have taken into consideration only 

 such observations as are indispensable for laying the first foundations 

 of meteorological science; some investigations of a more refined 

 character they may, probably, make the subject of a future report. 



As soon as the register of a month's observations has been com- 

 puted, it should be copied, and the copy carefully compared with 

 the original by two persons, one reading aloud from the original, and 

 the other attending to the copy, and then exchanging parts, — a pro- 

 cess always advisable whenever great masses of figures are required 

 to be correctly copied. 



A copy so verified should be transmitted regularly to such person 

 or public body, as, under the circumstances, may be authorized or 

 best adapted to receive and discuss the observations. 



