**From:**

**To:**

**Date:**

**Source of text:**

**Summary:**

Thanks JH for compliments on his book [Theory of Equations]. Requests JH's signature for his application to the R.S.L.

**Contributor:**

Isaac Todhunter

Sir John Herschel

[5 November 1861]

RS:HS 17.352

Thanks JH for compliments on his book [Theory of Equations]. Requests JH's signature for his application to the R.S.L.

John Herschel Project

Isaac Todhunter

Sir John Herschel

[6 April 1864]

RS:HS 17.353

Printing History of the Mathematical Theory of Probability. Inquires about a probability calculation of Wilhelm Struve's in JH's Outlines Astr.

John Herschel Project

Sir John Herschel

Isaac Todhunter

[7 April 1864]

RS:HS 24.37

Unable to find the calculation of Wilhelm Struve about which IT inquired. Will investigate the matter further.

John Herschel Project

Isaac Todhunter

Sir John Herschel

[11 July 1864]

RS:HS 17.354

Asks again about Wilhelm Struve calculation in Outlines Astr.

John Herschel Project

Sir John Herschel

Isaac Todhunter

[18 July 1864]

RS:HS 24.54

Cannot find the source of supposed Wilhelm Struve probability calculation; believes he has made a mistake. Regrets the error was not noticed in time to correct the seventh edition of Outlines Astr.

John Herschel Project

Isaac Todhunter

Sir John Herschel

[21 July 1864]

RS:HS 17.355

Thanks JH for looking into the Wilhelm Struve probability calculation; makes note of the change in his work.

John Herschel Project

Isaac Todhunter

Sir John Herschel

[30 May 1865]

RS:HS 17.356

Thanks JH for compliments on his work [History of the Mathematical Theory of Probability]. Suggests changes in the Wilhelm Struve probability problem.

John Herschel Project

Sir John Herschel

Isaac Todhunter

[4 July 1865]

RS:HS 24.116

Sends copy of paper on 'projection of the sphere in which the problem is to make any infinitely small figure on the projection similar to that on the sphere,' which he has presented to the Royal Geographical Society.

John Herschel Project

Sir John Herschel

Isaac Todhunter

[19 January 1866]

RS:HS 24.139

Describes the problem of 'probability of three points on a plane forming an acute triangle.' Notes Augustus De Morgan has the same solution to the problem.

John Herschel Project

Isaac Todhunter

Sir John Herschel

[2 February 1866]

RS:HS 17.357

Makes suggestions for the solution to the three point probability problem using integrals of infinity.

John Herschel Project