Second Report of the Meteorological Committee ^c. 383 



and be requested, until a Barometer can be procured, to fill 

 lip the column of the in-door Thermometer, with observations 

 of the Hygrometric state of the air, as ascertained by the 

 depression of temperature produced by wrapping the bulb in 

 wet linen or cotton, and suspending it freely in the manner 

 recommended in p. 12 of their Instructions. 



The Committee have also received from the Astronomer Royal, 

 and from Sir J. Hersciiel, hourly Observations at the Solstices 

 of December 1834, and June 1835, and the Equinox of March 

 J835, made according to the plan proposed in their printed 

 Instructions. The comparison of these observations has shown 

 that in this locality at least, even at stations so near together 

 as Feldhausen and the Royal Observatory, the fluctuations of 

 atmospheric pressure are very far from nicely corresponding, 

 and that, so long as any wind subsists in a mountainous 

 district, the atmospheric strata can by no means be regarded 

 as horizontal. The calm, however, having been complete and 

 uninterrupted for 10 successive hours on the night of the 22d 

 ult., afforded an excellent opportunity for determining- the 

 difference of level of the two stations, which appeai-s to be 

 129 feet 8 inches, subject to a trifling correction for the zero 

 points of the Barometer, which remains to be more exactly 

 ascertained. 



Communications have been received by the Committee from 

 Sir E. Ryax, Chief Justice of Calcutta, containing a Register 

 of the Barometer and Thermometer kept by himself during his 

 passage from Table Bay to Calcutta, in the months of Decem- 

 ber, January, and February 1834-5; from — McHardy, Esq, 

 Surgeon on board the Mount Stewart Elpliinstone, containing 

 a similar register made in the voyage of that ship from Table 

 Bay to London, during parts of the months of September and 

 October 1834 ; from Capt. Wauciiope, of H. M. S. Thalia, 

 containing extracts from a Journal of the Barometer and 

 Thermometer, &c. observed on board of H.M.S. Eurydice, off 

 Saldanha Bay, during a heavy gale in 1819, as also in Table 

 Bay during a violent North-wester in 1817; and lastly, _/ro»i 

 H. W. IxN'ES, Esq. Surgeon on board the Slitrbutne, containing 

 a similar register kept during the approach to and after the 

 arrival of that ship in Table Bay in January 1835. 



Of the two former of these communications (those of Sir 

 E. R VAN and of Mr. McHaudy), it must be observed that they 

 both, but especially the first, afford strong corroborative, and 

 indeed, quite decisive evidence of that important meteorological 

 fact of a considerable depression of the Barometer in ap])roach- 

 ing to the equator from cxtratropical latitudes. Sir E Ryan's 

 Barometer, previous to his sailing was compared, through the 

 medium of a portable Barometer in possession of Sir J; 



