'One of those superlative pieces of mechanism'

[willeica]

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9 hours ago, zeitz said:

Since dry plates were invented in 1871, this must be taken with a wet plate.

Correct, which would have meant having wet plate processing to hand at that altitude. It makes toting a Leica up Everest seem easy. At around the same time Carleton Watkins was using a lens from the same manufacturer and had a team of mules and a truck to lug his gear around to take wet plates in Yosemite which were eventually seen by Abraham Lincoln. You had to be tough and determined to photograph the wild in those days. There is some evidence that Bourne was, for a time, a dealer in Grubb lenses in India.

Here he is being mentioned in advertising from the mid 1860s. This may have appeared in the Journal at around that time, but Paul indicated earlier that some advertising had not been scanned .

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William

Edited February 13, 2021 by willeica

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[zeitz]

William, do you have an optical diagram of the Grubb Aplanatic lens?  I looked at your Grubb and Parsons article on Macfilos.

[pgk]

William won't mind as I have a digital copy of the original patent. From Thomas Grubb's original patent:

"And in further explanation of the nature and construction of my improved lens I give the accompanying sectional Drawings, of which Figure 1 represents and ordinary “view” lens and Figure 2 one of my improved lenses. a, a, in both Figures represent, flint glass, and b crown glass, both Figures representing compounds of the same focal length and external form, and compounded of lenses made of the same kinds of crown and flint glass and o( the same. foci respectively, but which differ essentially in their respective forms, and also occupy inverted places in their respective compounds, thus necessarily causing the inner or separating curve to be inverted, and also much deeper in my improved lens. It is in this great increase in the depth of the internal curvature that the great superiority of my improved lens mainly resides."

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Edited February 13, 2021 by pgk

[willeica]

1 hour ago, zeitz said:

William, do you have an optical diagram of the Grubb Aplanatic lens?  I looked at your Grubb and Parsons article on Macfilos.

 

8 minutes ago, pgk said:

William won't mind as I have a digital copy of the original patent. From Thomas Grubb's original patent: "

And in further explanation of the nature and construction of my improved lens I give the accompanying sectional Drawings, of which Figure 1 represents and ordinary “view” lens and Figure 2 one of my improved lenses. a, a, in both Figures represent, flint glass, and b crown glass, both Figures representing compounds of the same focal length and external form, and compounded of lenses made of the same kinds of crown and flint glass and o( the same. foci respectively, but which differ essentially in their respective forms, and also occupy inverted places in their respective compounds, thus necessarily causing the inner or separating curve to be inverted, and also much deeper in my improved lens. It is in this great increase in the depth of the internal curvature that the great superiority of my improved lens mainly resides."

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Thanks Paul. Here are other drawings with an explanation by Mr Grubb himself from 26th March 1858  to the Royal Dublin Society (RDS) where I am a member. As coincidence would have it, two years ago I arranged another talk at the RDS by a photographic expert, none other than our good friend Paul (pgk). The topic was his underwater photography. So Paul followed in the footsteps of Mr Grubb 161 years later.

William

 

Edited February 13, 2021 by willeica

[zeitz]

This web site adds a little more information to understand the differences and improvements between achromats and aplanats.

https://www.photonics.com/Articles/Understanding_Lenses_Aplanats_and_Achromats/a22346