(48) REMAIIKS. [aPP. NU. 



of that and the noon of the preceding day, or an interval 

 corresponding with tlie day by nautical computation ; con- 

 sequently the " medium" column represents the state of the 

 Barometer (nearly) on the first mid-night, or beginning of 

 each day. 



The registers of the first six years, from 1807 to 1812 

 inclusive, have already been laid before the Public, in the 

 " Memoirs of the Wernerian Natural History Society *." 

 As, on comparison with the present series, tliere Avill appear 

 some dissimilarity, to prevent a hasty censure of inconsis- 

 tency, some explanation seems proper. The " latitudes," 

 " longitudes,'' " force of wind," and " meteors," as publish- 

 ed in the Wernerian Memoirs, will be found to agree with 

 this series, excepting so far as the necessary abridgment in 

 the remarks on the weather, may have caused some things 

 to appear in the one, which do not appear in the other. 

 The thermometrical observations in this series, though 

 extended in their plan, and carried to decimals of a de- 

 gree in the column " medium," will be found to cor- 

 respond, as nearly as possible, with the column headed 

 " Thermometer," in the Wernerian Memoirs, excepting 

 in the case of three or four trifling typographical errors, 

 and a few instances where the fractions of a degree had 

 been omitted ; the fraction of one day in excess com- 

 pensating lor the deficiency of a similar fraction on a sub- 

 sequent day. The means of the two series, however, will 

 be found the same. The plan of the barometrical regis- 

 ter being now also altered and extended, occasions some 

 dissimilarity betAveen the two series. The apparent diffe- 

 rence is thus produced. In the registers in the Wernerian 

 Memoirs, the state of the Barometer at noon, only is given ; 

 but having, in my original journals, inserted the highest 

 and lowest of the mercury at every change, I have been en- 

 abled now to give the extremes of pressure during each day, 

 for every year, excepting the first three. Hence, though 

 some of the daily observations seem to disagree in the two 

 series, the means of each month are not essentially different. 

 The direction of the winds will appear to be totally different 

 throughout the two series. This arises from the winds in 

 the Tables first published being quoted according to the 

 magnetic meridian, while those now presented to the pubUc, 

 have, by the application of the variation, been reduced to 

 the true meridian. 



* Vol. i. p. 249. and 609;— and vol. ii. p. 155, and 16T. 



No. II. 



