REPORT OF THE KEW COMMITTEE. li 



Two Standard Barometers have been purchased from Adie, and tested at 

 Kew, one of which has becu forwarded to the Chief Signal Office, Washington, 

 and the other to Prof. Jack, of Fredricton, New Brunswick. 



Tubes for the construction of a Welsh's Standard Barometer on the Kew 

 pattern, together with the necessary metal mountings, and a Cathetometer, 

 have been made under the superintendence of the Committee for the Chief 

 Signal Office, Washington. 



The Committee have likewise superintended the purchase of meteorological 

 instruments for Owens College, Manchester, and for the ObseiTatory attached 

 to the University of Fredricton, New Brunswick. 



The Kew Standard Thermometer (M. S. A.), divided arbitrarily by the late 

 Mr. Welsh, and employed for many years past as the standard of reference 

 in the testing of thermometers, was accidentally broken on the 3rd of January. 

 Since then a Kew Standard, of the ordinary construction, made in 1866, and 

 which had been compared on several occasions with M. S. A., has been used 

 to replace it. 



Copies of some of the meteorological observations made at Kew during the 

 years 1869 and 1870 have been supplied to the ^Institution of Mining 

 Engineers at Newcastle-upon-Tyne, and the Editor of Whitaker's Almanac, 

 the cost of the extraction being paid by the applicants in both instances. 



A set of self-recording meteorological instruments, the property of the 

 Meteorological Committee, have been erected in the Verification-house, and 

 are now undergoing examination.';' 



The self-recording metereological instruments now in work at Kew will be 

 again mentioned in the second division of this Eeport. These are in the 

 charge of Mr. Baker. 



3. PhotoJieJiocjraph.—Thc Kew Heliograph, in charge of Mr. Warren De 

 La Rue, continues to be worked in a satisfactory manner. During the past 

 year 362 pictures have been taken on 205 days. The prints from the 

 negatives alluded to in last Report have been taken to date, and the printing 

 of these has become part of the current work of the estabHshment. A paper 

 by Messrs. Warren De La Rue, Stewart, and Loewy, embodying the position 

 and areas of sim-groups observed at Kew during the years 1864, 1865, and 

 1866, as well as fortnightly values of the spotted solar area from 1832 to 

 1868, has been published in the Philosophical Transactions, and distributed 

 to those interested in solar research. A Table exhibiting the number of 

 sun -spots recorded at Kew during the year 1870, after the manner of 

 Hofrath Schwabe, has been communicated to the Astronomical Society, and 

 published in their ' Monthly Notices.' 



An apparatiis is being constructed under the direction and at the expense 

 of Mr. Warren De La Rue, and it will shortly be erected on the Pagoda in 

 Kew Gardens, in order to be employed in obtaining corrections for optical 

 distortion in the heliographical measurements. 



4. Miscellaneous ivorl: — Experiments are being made on the heat produced 

 by the rotation of a disk in vacuo. 



A daily observation has been made with the Rigid Spectroscope, the 

 property of Mr. J. P. Gassiot. 



Observations have been made with two of Hodgkinson's Actinometers, 

 the property of the Royal Society, in order to compare them with the 

 Actinometers deposited at the Observatory, for reference, before forwarding 

 them to India. 



The Committee have siiperintended the purchase of optical apparatus, 

 chemicals, &c. for the Observatories at Coimbra and Lisbon. 



