My dear Sir,
In reply to your kind letter of the 6th of December, I regret exceedingly that the number of my engagements prevents me from writing you a short paper as I should wish to do on the use of small apertures by amateurs in astronomy.
I am clearly of opinion that the work that can be done with small apertures is far from exhausted; the advantages of large apertures are not as great as is generally supposed, such instruments have serious drawbacks; for instance it is seldom that the atmosphere is not good enough to make successful observations with a telescope of 3" aperture, but here in England at all events the nights that 6" of aperture can be used with the best results are comparatively few.
The use of small apertures is a most valuable training for observers, they are encouraged to improve the keenness of their vision by observation instead of trusting to more light and higher magnifying power.
I know many observers who can see the snow caps on the poles of Mars with a 3" aperture, though 6" of aperture is generally considered to be necessary for the purpose.
I know one Lady who gets excellent views of the spectra of the larger stars with 2½" object glass and a McCleans Star Spectroscope, the two instruments complete cost only £12.10.0.
Again I have known many observers who have done admirable work with telescopes of 4" aperture and have been induced to obtain telescopes of 8" aperture but they have never done better work with them than with the smaller apertures.
I should like to go on adding illustrations to this but time prevents me.
Trusting these few remarks will show my opinion on hte subject and begging you to excuse my brevity. With best wishes for the success of your Society
G.E. Lumsden Esq
719 Ontario Street
|John Browning Letter, 1891 Jan 8 (DJVU - low quality)||233.66 KB|
|John Browning Letter, 1891 Jan 8 (DJVU - high quality)||2.14 MB|
|John Browning Letter, 1891 Jan 8 (PDF)||700.01 KB|