REPORT OF THE KEW COMMITTEE. xlj 
a physical and not an instrumental origin, and purpose communicating their 
results in a joint paper to the Royal Society. 
3. Meteorological Work—The meteorological work of the Observatory 
continues in the charge of Mr. Baker, who executes his duties very satis- 
factorily. 
Since the Dundee Meeting, 78 Barometers have been verified, and 71 are 
at present in hand; 1139 Thermometers have likewise been verified, and 14 
Standard Thermometers have been constructed for the Thermographs of the 
Meteorological Committee. 32 Thermograph Thermometers have likewise 
been tested, 24 of these being for the Meteorological Committee and 8 for 
opticians. 
The self-recording meteorological instruments now at work at Kew will 
be again mentioned in the second division of this Report. These are in the 
charge of Mr. Baker, the Photography being superintended by Mr. Page. 
Mr. Robert Addams has kindly made a preliminary experiment with his 
apparatus for freezing carbonic acid, which is now at Kew, and has also 
left specific instructions regarding it, so that the operation can in future be 
performed without assistance. The point corresponding to the temperature 
of freezing mercury has been determined for two Thermometers belonging to 
the Meteorological Committee. 
The Self-recording Barographs, Thermographs, and Anemographs for the 
six outlying Observatories of the Meteorological Committee have been verified 
at Kew. A Self-recording Barograph and Thermograph have likewise been 
verified for Messrs. R. and J. Beck, opticians ; and the verification of another 
set for Mr. Chambers, of the Colaba Observatory, has been very recently 
completed. 
The experiments made on Aneroids at Kew, by the request and at the ex- 
pense of the Meteorological Committee, have formed the subject of a com- 
munication recently made to the Royal Society by that body. 
4. Photoheliograph.—The Kew Heliograph, in charge of Mr. De La Rue, con- 
tinues to be worked in a satisfactory manner. During the past year 224 
negatives have been taken on 140 days. 90 pictures of the Pagoda in Kew 
Gardens have likewise been taken, in the hope of being able by this means 
to determine accurately the angular diameter of the Sun. 
Since the last Meeting of the Association, a series of solar researches, 
in continuation of the second series, has been published (the expense of 
printing having been defrayed by Mr. De La Rue), entitled ‘ Researches on 
Solar Physics. Appendix to Second Series.—On the Distribution in Helio- 
graphic Latitudes of the Sun-spots observed by Carrington; by Messrs. De 
La Rue, Stewart, and Loewy.” 
Two papers have likewise been communicated to the Royal Society by 
these gentlemen. The first of these is entitled “‘ Researches on Solar Physics. 
Helographical Positions and Areas of Sun-spots observed with the Kew 
Photoheliograph during the years 1862 and 1863.” 
The second is entitled “* Account of some Recent Observations on Sun-spots, 
made at the Kew Observatory.”’ 
Sun-spots continue likewise to be numbered after the manner of Hofrath 
Schwabe; and a Table, exhibiting the monthly groups observed at Dessau 
and at Kew for the year 1867, has been communicated to the Astronomical 
Society, and published in their Monthly Notices. 
The measurements of the Kew pictures for the year 1864 are approaching 
completion; when complete, they will be communicated to the Royal 
Society. It is intended to work up rapidly the back years, preparatory to 
a final discussion. 
