120 REPORT — 1844. 



These data may rot at first sight appear important ; they are however of 

 great value in practice, as the ceconomy of the fuel and the efficiency of the 

 furnace in a great measure depend upon the lieight of the bridge behind, 

 which operates as a rctarder of the currents in the same way as the damper 

 is used for checking the draught of the chimney in the flues. 



Mr. Murray further treats of the temperature of the furnace, flues, &c., 

 but these points having already been experimented upon and fully discussed 

 in the report, it will not be necessary to notice them in this place. 



William Fairbairn. 



Report concerning the Observatory of the British Association, at Kew, 



from August the 1st, 1843, to July the ^\st, 1844. 



By Francis Ronalds, Esq., F.R.S. 



In August of last year (1843) I drew up a short account of the electrical 

 observatory here, as fitted up and supplied with ins^trunients under my direc- 

 tion, and principally in accordance with a plan which I Lad in November 

 1842 stated to Professor Wheatstone, 



That account was annexed to a journal of about one month's electrical ob- 

 servations made therewith, and the meteorological journal commencing in 

 October 1842. 



From August 1843 to the present time a similar electrical journal has been 

 maintained with all the attention to accuracy which our ways and means have 

 permitted, and it has been presented to the Association in a condensed tabu- 

 lar form embodied with the other meteorological observations made here. 



But as the above-mentioned statement may be deemed not quite sufficient 

 for a due appreciation of the circumstances under which our journal has been 

 kept, as I have since made a few variations in and additions to the collection 

 of instruments, given to the journal a different form*, and instituted a few 

 test and other experiments, it seems expedient to comprise in this report, 

 first, a short description of the building itself, and of the whole meteorological 

 apparatus employed; secondly, some necessary explanations, and a specimen 

 of the journal ; thirdly, a brief statement relative to all the experiments (of 

 ani/ moment) which have been made. 



I. Description of the Observatorg and of Instruments used for the Observations. 



The Building. 



The position, form, Sfc. of the structure (Plate XXX. fig. 1), are certainly 

 very favourable to electrical meteorology. It was erected for His Ma,jesty 

 George 111. by Sir William Chambers, in about the year 1768, in the old 

 Deer Park, Richmond, upon a promontory formed by a flexure of the river, 

 its least distance from which is 924 feet. The nearest trees (elms) are about 

 13 feet lower than the top of the conductor. Some elms more distant average 

 about 13 feet lower, and the trees of various kinds, as elm, beech, poplar, &c., 

 on the bank of the river, about 8 feet lower. Innumerable high trees exist in 

 the royal pleasure-grounds, the nearest being about half a mile distant. 



The height of the top of the conductor above the level of the sea is about 

 feet; above the river, at low Avater, about 83 feet, and above the top of 

 the dome 16 feet. 



* As nearly like the Astronomer Royal's as possible. 



