Thinks that aluminum coating on telescope mirrors may work [see FK's 1856-10-9]; also suggests looking into flouric glass containing aluminum for lenses of low dispersion power.
Showing 21–40 of 159 items
Thinks that aluminum coating on telescope mirrors may work [see FK's 1856-10-9]; also suggests looking into flouric glass containing aluminum for lenses of low dispersion power.
Will give him great pleasure to call at Collingwood in the near future. Grieved to hear of JH's illness. Begs acceptance of a set of papers of Dr. William Griffith.
Sends another pamphlet on the gold question. On the last page he will find JM has adopted JH's suggestion, though he does not give the source. Thinks that these suggestions should prove useful to France.
Sends some photographs with comments. Pleased to hear JH is in much better health. Received a circular from U. J. J. Leverrier requesting meteorological information. Sends meteorological observations made at the Observatory during the last fourteen years.
Recently came across some instructions JH had drawn up for persons who are color blind. Sends a note explaining the work of William Pole on this same subject. Has left the manufactory at Ipswich.
Forwards the draft of the words of the Memorial to be presented to Her Majesty. Nonmembers of the League have signed. On receipt of JH's reply will forward the written headings for JH's signature.
The Admiralty has given a grant for an astronomical expedition to the Peak of Teneriffe, and JH is now providing a list of details that should be observed in such an expedition.
Compliments JB on publication of 'Trigonometry of the Parabola.' Recalls JH's papers on catenaries.
Responds to Hubbard's inquiry about coinage.
Deposit enclosed money at Cadet House for John Herschel's readmission [to Addiscombe].
Celebration planned for arrival of MH and IH. Son John is home from Addiscombe. JH's health. News of Hawkhurst. Regards to Mr. and Mrs. Greig.
JH's recommendations to Admiralty regarding experiments to be conducted by expedition to Teneriffe led by C. P. Smyth.
Encourages JH to contest Cambridge University seat in Parliament, following death of Henry Goulburn.
Writes to clarify his understanding of the word 'fluorescence.' Asks JH to review a paper on color-blindness.
Comments on GS's ideas [see GS's 1856-6-27] about the nature of fluorescence. Asks for strong horseshoe magnets from R.S.L. to try to solve the problem of 'Mahomet's coffin.'
Further thoughts [see GS's 1856-6-27] on the nature of fluorescence, including that it is a transient phosphorescence.
Continues comments on fluorescence from letter of 1856-7-8; then shows mathematically that JH's solution for the problem of Mahomet's coffin [see GS's 1856-7-1] will not work.
Thanks for the magnetic theory [see GS's 1856-7-9] and agrees it argues against JH's ideas about Mahomet's coffin. Describes some interesting magnetic experiments JH has seen.
Comments on one of the magnetism experiments JH described in his letter of 1856-7-14.
Where in JH's evidence to Parliamentary Decimal Commission did JH give number of coins that require recoinage?