Search: Herschel, John in correspondent 
Forbes, James David in correspondent 
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John Herschel Project in contributor 
1840-1849::1840 in date 
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From:
Sir John Herschel
To:
James David Forbes
Date:
[3 March 1840]
Source of text:
St. Andrews 12 (C: RS:HS 25.6.1 & TxU:H/L-0157; Reel 1054)
Summary:

Outlines theory behind and method for preparing thermographic paper, which allows observers to determine 'what share each ray of the spectrum bears in producing the observed total effects.'

Contributor:
John Herschel Project
From:
James David Forbes
To:
Sir John Herschel
Date:
[9 March 1840]
Source of text:
St. Andrews LB III 71, 72 (C: RS:HS 7.295)
Summary:

Would like to know the degree of sensibility to heat of JH's paper. The paper of W. H. F. Talbot is useless for his purpose as only violet heat affects it. Did JH use a flint glass prism for his spectrum experiments? Has he ever used photography to show the impression of polarization and diffraction?

Contributor:
John Herschel Project
From:
Sir John Herschel
To:
James David Forbes
Date:
[13 March 1840]
Source of text:
St. Andrews 13 (C: RS:HS 22.44)
Summary:

On the preparation of paper to exhibit a thermal spectrum.

Contributor:
John Herschel Project
From:
James David Forbes
To:
Sir John Herschel
Date:
[4 June 1840]
Source of text:
RS MM.16.137
Summary:

Explains results obtained by R.S.L. subcommittee considering state of meteorological journal published in R.S.P.T. Wonders about feasibility of establishing 'simple but accurate meteorological register' under public authority.

Contributor:
John Herschel Project
From:
Sir John Herschel
To:
James David Forbes
Date:
[10 June 1840]
Source of text:
St. Andrews 34 (Adraft: TxU:H/L-0158 & -0145.2; Reel 1054 & C: RS:HS 22.44)
Summary:

R.S.L. will deviate from its intellectual purpose whenever it meddles in practical observations. Proper role for R.S.L. is to suggest goals and methods and to reward discoveries. Recommends discontinuing meteorological observations at Somerset House; other stations now provide better data. If R.S.L. insists on establishing a meteorological register, JH suggests one like that of J. F. Daniell.

Contributor:
John Herschel Project
From:
James David Forbes
To:
Sir John Herschel
Date:
[11 June 1840]
Source of text:
RS MM.16.138 (C inc: TxU:H/M-0145.3; Reel 1087)
Summary:

Describes difficulties in attempting to produce good meteorological register and establish national meteorological observatory.

Contributor:
John Herschel Project
From:
Sir John Herschel
To:
James David Forbes
Date:
[10 August 1840]
Source of text:
St. Andrews 42 (C: RS:HS 22.62)
Summary:

Explains efforts at using a makeshift apparatus for 'fixing the spectrum.' Discusses current confusion and ultimate hope surrounding JF's meteorological recommendations. In a postscript, notes observations of meteors in Persei.

Contributor:
John Herschel Project
From:
James David Forbes
To:
Sir John Herschel
Date:
[17 August 1840]
Source of text:
St. Andrews LB III, 120-2 (C: RS:HS 7.296)
Summary:

Thanks for JH's letters and the paper on photography with special reference to the effects of heat. Was present at the R.S.L. during consideration of a national observatory. Would like JH's opinion. Is working on a supplementary report on meteorology.

Contributor:
John Herschel Project