Is insistent that JH cannot perform the functions of Foreign Secretary [of the R.A.S.] as he has too much to do already, and has had to give up much of his personal scientific correspondence.

Offers to provide committee with plans for and to supervise construction of new instrument, devised by JH, for study of solar spectrum.

Welcomes ER back to England. Met ER's host, Charles Babbage, at Greenwich yesterday. Wants to visit before ER departs for Geneva, but JH's wife is ill. Based on accounts of Geneva by ER's wife, JH sent three oldest daughters and their governess to spend summer there.

Acknowledges JH's payment for stationery for Breslau magnetic observatory.

Sends JH samples of his calotypes. Off to Germany on a photographic expedition.

Carl Steinheil has proposed making telescope mirrors by plating silver on glass. Is writing to JH to tell him that somewhat earlier he had included this process in one of his patents.

Encloses JB's letter [21 Dec. 1841] to Chancellor of Exchequer [H. Goulburn] advocating adoption of metric system. Hopes [members of Standards Commission] will not consider JB obstinate. Admits that JH's opposition to system has advantage of authority and conservatism.

Papers arrived safely. Will report GD's opinion on these soon.

Sees too many difficulties in optics of JH's proposed telescope. Can build mechanical portion, but not by March as JH requires. Cannot give estimate, because design is too novel.

Will begin building components that JH identified as most immediately needed. Confirm scale of JH's drawings. Will send samples of prism glass for JH to inspect. Cannot yet estimate cost.

Does JH plan to publish 'Treatise on Light' in separate form?

Asks whether JH will be prepared to give the committee report on systems of simultaneous magnetical and meteorological observations at the B.A.A.S. meeting on 23 June.

Asks whether JH will be prepared to present the committee report on N. L. Lacaille's stars at the B.A.A.S. meeting on 23 June.

JH, William Whewell, George Peacock, Humphrey Lloyd, and Edward Sabine are appointed by the B.A.A.S. to study systems of simultaneous magnetical and meteorological observations. They will be granted £89.

Hopes royal observatory at Cape of Good Hope will relieve Ordnance department. U.S. government agreed to pay for publication of observations there. A. D. Bache favors continuance of hourly meteorological observations in U.S. for one year. G. A. Erman will attend meeting at Cambridge. German translations by ES's wife.

Urged by G. B. Airy, ES withdraws earlier letter to JH and encloses letter with ES's opinions regarding continuance of [magnetic and meteorological] observations.

Asks JH to inspect first magnetic and meteorological observations from [Tasmania] and Toronto. Hopes North American observations will be increased.

Encloses bill from W. H. Allen & Co. regarding Breslau observatory. [JH annotation: Details of bill.]

Encloses newspaper clipping that reports JH is member of commission of inquiry on weights and measures. Protests that the poor are defrauded more by false scales than by nonstandard weights. Proposes remedy.

GP's views on continuation of magnetic observatories in colonies.