had been found in regulating the temperature of the Magnetic Basement, but it was anticipated that in future there would be no difficulty in keeping down the annual variation within about 5° and the diurnal variation within 3°.--Longitudes in America were determined in this year by way of Valencia and Newfoundland: finished by Nov. 14th." Of private history: In April he made a short visit to Ventnor in the Isle of Wight.--From June 15th to July 23rd he was on an expedition in Norway with his son Osmund and his nephew Gorell Barnes.--There was probably a short stay at Playford in the winter. In this and in the previous year (1865) the free-thinking investigations of Colenso, the Bishop of Natal, had attracted much notice, and had procured him the virulent hostility of a numerous section. His income was withheld from him, and in consequence a subscription fund was raised for his support by his admirers. Airy, who always took the liberal side in such questions, was a subscriber to the fund, and wrote the following letter to the Bishop: ROYAL OBSERVATORY, GREENWICH, S.E., _1865, July 24_. MY LORD, With many thanks I have to acknowledge your kind recollection of me in sending as a presentation copy the work on Joshua, Judges, and especially on the divided authorship of Genesis; a work whose investigations, founded in great measure on severe and extensive verbal criticism, will apparently bear comparison with your Lordship's most remarkable examination of Deuteronomy. I should however not do justice to my own appreciation if I did not remark that there are other points considered which have long been matters of interest to me. On several matters, some of them important, my present conclusions do not absolutely agree with your Lordship's. But I am not the less grateful for the amount of erudition and thought carefully directed to definite points, and above all for the noble example of unwearied research and freedom in stating its consequences, in reference to subjects which scarcely ever occupy the attention of the clergy in our country. I am, My Lord, Yours very faithfully, G.B. AIRY. _The Lord Bishop of Natal_. * * * * * Here also is a letter on the same subject, written to Professor Selwyn, Professor of Divinity at Cambridge:-- ROYAL OBSERVATORY, GREENWICH, LONDON, S.E., _1866, May 5_. MY DEAR SIR, The MS. concerning Colenso duly arrived. I note your remarks on the merits of Colenso. I do not write to tell you that I differ from you, but to tell you why I differ. I think that you do not make the proper distinction between a person who invents or introduces a tool, and the person who uses it.