Sends copy of ST's Progress of Philosophy in the Past and in the Future.

Attempts to clear up a misstatement made before the Society by J. C. Dyer concerning JH's views in regard to optics, especially in relation to the luminiferous ether.

Received JH's note. Will vote as JH advised. Bill is scheduled [to be read] on 13 May.

JH's account of his own health is much better than he hoped for. Has he seen AD's contribution to English?

[Printed notice] Invitation to meetings of 'Royal Geographical Society.'

Observations on various forms of [hemianopsia], which afflicts HA, his father [G. B. Airy], and JH. Detailed description of recent attack. Seven sketches with captions.

Thanks for JH's notes on metric system. Will study these before Parliamentary debate on 13 May. Calculates that 63 percent of exports go to British possessions, while only 18 percent go to Continent. Sees this as argument against introducing metric system.

Addresses problems in metric bill introduced to Parliament by William Ewart. Argues for the retention of the British system of weights and measures. Shows that the inch can be defined as one five hundred millionth of the length of the earth's polar axis.

Encloses papers from J. B. Smith, supporter of weights and measures bill. [JH's daughters] Maria and Amelia visited House [of Commons] yesterday, but ladies's gallery was full and they could not observe proceedings. Trial of American president [Andrew Johnson] is political farce.

JH is bound by promise to J. M. Cameron not to sit for portraits by other photographers. Will not sign photograph of JH sent by JS if this is intended for publication. Offers to write article on musical scale for Quarterly Journal of Science.

Why did French chose arc from Dunkirk to Barcelona as basis for metric measurements? Explain meridian lines. Why are linear metric measurements founded on arc, rather than on straight line? Criticizes William Ewart for introducing metric bill.

Returns petition to JH. Read JH's paper. Venomous propositions [in House of Commons].

JH's approval encourages HA to publish account [of hemianopsia]. JH may keep HA's drawings. Notes on attack suffered by JH.

Comments on several aspects of poetry, including EC's; JH has been quite ill; talks about walking on water with a water velocipede.

Informal request for JH to write biography of W. R. Dawes for R.A.S. Recent marriages in CP's family.

Sees what a majority William Ewart's bill had yesterday. Comments on the events leading to this. So glad of the marriage of Amelia Herschel.

JH's views on relation of British Imperial measures to length of Earth's axis were misrepresented in 18 May article. Explains them in detail. Notes scientific basis of British system.

Speaks of the awkwardness of some telescopic instruments, but urges son John to persevere; comments favorably on daughter Amelia's prospective husband, Thomas Wade, and comments disparagingly about the government's introduction of a metrication bill.

More on musical scales [see GA's 1868-4-3]; GA here proposes the use of hyperbolic logarithms to help establish the scales.

Not well enough to attend Visitation Day at the Royal Observatory; fears JH will not likely attend any future meetings and should perhaps withdraw from the Board of Visitors.