no image
Lot 347
HERSCHEL, Sir JOHN FREDERICK WILLIAM (1792-1871, astronomer)
Sold for £840 (US$ 1,290) inc. premium

Lot Details
HERSCHEL, Sir JOHN FREDERICK WILLIAM (1792-1871, astronomer)
AUTOGRAPH LETTER SIGNED ('JFWHerschel'), ABOUT SUN SPOTS, to the amateur astronomer and correspondent of Darwin, the Rev. Frederick Howlett: illustrating his points about Sun Spots that he has looked at for Howlett with two pen and ink sketches, Herschel explains that the colours Howlett described are evidently owing to achromatism in the eye-piece and what he needs is a good achromatic object-glass, preferably of the type he has himself constructed, which has the concave lens turned towards the light ('...This construction which is equally achromatic and aplanatic at all distances - is equally well adapted for a microscope object glass & for a telescope one - a property which belongs to no other construction...'), concluding that he has no doubt that 'the use of such a lens as an eyepiece would infinitely improve the definition of the projected image and shew the true colours (if any) of the Spots...', 3 pages, octavo, some minor spotting, recipient's name written in red crayon at head, spindle hole in upper left-hand corner, Collingwood, 26 January 1864

Footnotes

  • Herschel made important contributions to the study of the Sun in general and to sun spots, telescopes, lenses and the mottled nature of the Sun's surface in particular. He was also a pioneer of photography.
Auction information

This auction is now finished. If you are interested in consigning in future auctions, please contact the specialist department. If you have queries about lots purchased in this auction, please contact customer services.

Buyers' Obligations

ALL BIDDERS MUST AGREE THAT THEY HAVE READ AND UNDERSTOOD BONHAMS' CONDITIONS OF SALE AND AGREE TO BE BOUND BY THEM, AND AGREE TO PAY THE BUYER'S PREMIUM AND ANY OTHER CHARGES MENTIONED IN THE NOTICE TO BIDDERS. THIS AFFECTS THE BIDDERS LEGAL RIGHTS.

If you have any complaints or questions about the Conditions of Sale, please contact your nearest customer services team.

Buyers' Premium and Charges

For all Sales categories excluding Wine, Coins & Medals and Motor Cars and Motorcycles:

Buyer's Premium Rates
25% on the first £50,000 of the Hammer Price
20% from £50,001 to £1,000,000 the Hammer Price
12% from £1,000,001 of the Hammer Price

VAT at the current rate of 20% will be added to the Buyer's Premium and charges excluding Artists Resale Right.

Payment Notices

Payment in advance: by cash, check with banker's card, credit card, bank draft or traveler's cheque.

Payment at collection: by credit or debit card.

Credit card charges: a surcharge of 2% is applicable when using Mastercard, Visa and overseas debit cards.

Shipping Notices

For information and estimates on domestic and international shipping as well as export licenses please contact Bonhams Shipping Department.

Contacts
  1. Customer Services (UK)
    Customer Services
    Bonhams
    Work
    Work +44 20 7447 7447
    FaxFax: +44 20 7447 7401
  2. Books (UK)
    General Enquiries
    Bonhams
    Work
    Work +44 20 7393 3828
    FaxFax: +44 20 7393 3879
  3. Shipping (UK)
    Logistics - Shipping
    Bonhams
    Work
    Work +44 20 7468 8302
    FaxFax: + 44 20 7629 9673
Similar Items