Search: Herschel, John in correspondent 
Pritchard, Charles in correspondent 
1860-1869 in date 
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From:
Charles Pritchard
To:
Sir John Herschel
Date:
[23 June 1860]
Source of text:
RS:HS 14.80
Summary:

Asks JH's opinion on CP's eclipse observations plans, especially on which equipment to use. Intends to use a 'diagonal solar eyepiece' during the eclipse. Plans to observe carefully and to sketch solar flares.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[28 July 1860]
Source of text:
RS:HS 14.81
Summary:

Sends observations of eclipse; asks JH to check accuracy. Details observations with diagonal solar eyepiece. Describes solar corona and lists bright stars visible during totality.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
31 July [1860?]
Source of text:
RS:HS 14.110
Summary:

Problems making actinometer observations during solar eclipse. Reports he did not observe the supposed planet Vulcan, but a fixed star. Sends micrometer observations. Describes shape of prominences.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[10 June 1861]
Source of text:
RS:HS 14.82
Summary:

Observes and measures sunspots. Takes spectrum of solar photosphere; detects sodium and magnesium absorption lines. Pleased with Alexander Herschel's work on the solar spectrum; wishes he would begin work on stellar spectra.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[19 October 1863]
Source of text:
RS:HS 14.83 Ada Pritchard, Charles Pritchard: Memoirs of His Life, 240-1
Summary:

Warren de La Rue observes 'willow leaves' [mottling on solar surface]. Diagonal solar eyepiece works with great success. Praises de La Rue's work as having astounding accuracy.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[15 December 1863]
Source of text:
RS:HS 14.84
Summary:

Describes debate at R.A.S. over the nature of the 'willow leaves.' Different parties argue that the 'leaves' are solid, precipitate, or non-luminous gas.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[16 January 1864]
Source of text:
RS:HS 14.85
Summary:

Thanks JH for solar observations. Discusses 'willow leaves' observations made at Greenwich Observatory after following JH's suggestions for solar eyepiece.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[20 January 1864]
Source of text:
RAS:JH Archive 15/5.2; Reel 11
Summary:

Gratitude for JH's gift of Caroline Herschel's autograph manuscripts to R.A.S.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[24 January 1864]
Source of text:
RS:HS 14.86
Summary:

Asks JH for information on the Beaufoy Clock owned by R.A.S., which is now missing. Requests JH to read R.A.S. Annual Report.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[8 February 1864]
Source of text:
RS:HS 14.87
Summary:

Thanks JH for reading R.A.S. records. G. P. Bond will not receive R.A.S. medal. The Beaufoy Clock is recovered.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[20 February 1864]
Source of text:
RS:HS 14.88
Summary:

Richard Hodgson claims to have invented the diagonal solar eyepiece despite JH's description of it in Cape Results.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[21 February 1864]
Source of text:
RS:HS 14.89
Summary:

Richard Hodgson pursues claim to invention of the diagonal solar eyepiece while claiming that JH disclaimed the invention.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[31 March 1864]
Source of text:
RS:HS 14.91
Summary:

Forwards letter concerning 'solar bright particles' by W. R. Dawes. Inquires if diagonal solar eyepiece used in JH's solar spectrum observations.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[9 November 1864]
Source of text:
RS:HS 14.92
Summary:

Compares W. L. Newman's and CP's calculations of optical coefficients to those in JH's work. Sends JH formulae and tables for calculating telescopic lens thickness and shape in relation to the dimensions of the telescope. Wishes JH luck on Iliad.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[10 November 1864]
Source of text:
RS:HS 14.93
Summary:

Compares JH's equation for lens curvature with that of C. F. Gauss.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[24 November 1864]
Source of text:
RS:HS 14.94
Summary:

Praises JH's Iliad. Asks R.S.L. for funds to cover expenses incurred by spherical observations. Details information to be included in optical tables.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[21 December 1864]
Source of text:
RS:HS 14.95
Summary:

Requests JH's reflections on the deceased Wilhelm Struve. Discusses making of telescope object glass. Continues work on the optical tables.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[11 February 1865]
Source of text:
RS:HS 14.96
Summary:

R.S.L. approves of CP's optical work, believing it will be helpful at observatories abroad. CP comments on Alexander Herschel's prism experiments.

Contributor:
John Herschel Project
From:
Charles Pritchard
To:
Sir John Herschel
Date:
[6 October 1865]
Source of text:
RS:HS 14.97
Summary:

Asks if JH anticipated the results of W. L. Newman's work on lens curvature.

Contributor:
John Herschel Project
From:
Sir John Herschel
To:
Charles Pritchard
Date:
1866
Source of text:
RS:HS 14.101 (C: RS:HS 24.182)
Summary:

Discusses opinions of Charles Darwin's theories. Doubtful that the day has shortened due to tidal forces since the earth's beginning. Alexander Herschel helps in the revision of William Herschel's double star catalogue. Alex is preparing to lecture at Glasgow University.

Contributor:
John Herschel Project