Offered for sale here is a unique handwritten manuscript work which focusses on the human eye with a predominant focus on the optical physics of how light passes through the eye, and another large focus on medical practice and the ways in which medical issues with the eye can be diagnosed and remedied, such as with lenses.
This manuscript was written by Frederick W. Ginger and dated to 13th November 1899 on the front free endpaper.
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There is some evidence this was used as a studying book for the author to become a doctor.
The scientific study throughout the book is of note, with a focus on optical physics now very widely known such as the 'principal point' (principal focus, or focal point), 'focal length', 'R power of cornea' (resolving power of the cornea lens), 'focal length of cornea alone: 32mm', etc. There are several measurements of optical distances with a rather accurate resolution with measurements as small as 6 mm. The page with this information has a labelled optical diagram of the eye to the reverso and there are several other illustrated diagrams throughout.
Some quotes taken which show use in a medical context include: 'amplitude depends on age', 'range depends on R condition of the eye', the diagnostic list for myopia with causes such as 'excessive use of the eye in close work are the direct reasons especially when they are accompanied by anything which impairs sight such as astigmatism'. There is similar attention to other conditions such as anisometropia, 'simultaneous V', astigmatism, irregular astigmatism, presbyopia, cataract, glaucoma, sympathetic ophthalmia, etc. There is also a section on the use of the ophthalmoscope, both directly and indirectly.
There are some simple mathematical calculations such as calculating image distance through a lens and this is then applied 'to calculate retinal image', calculating the index of refraction, calculation of distances of images through convex and concave lenses from the object location with ray diagrams to illustrate this, calculating lens magnification and subsequent image size, a relatively more complex formula for finding F, calculations for the Rx 'for case of mixed astigmatism', 'for case of compound H + compound M', etc. Also quite a cool formula for calculating the principal angle of deviation of a prism and some look at uncertainties in measurements.
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Potentially the Frederick William Ginger born December 1877 in the Aylesbury district of Bucks. He married Augusta Durran September 1907 at Banbury and they had a daughter Rhoda M Ginger born March 1912 at Banbury.
Size: 18 x 22.5 cm (approx.)
Condition:
Bound in quarter leather over marbled boards with no external identifying features (title, author, gilt, etc). Spine discoloured slightly with some wear and a small hole. Boards with some scuffs and edge wear but remain structurally sound. Some rather humorous drawings to front pastedown and verso ffep with ownership inscription 'Fred W. Ginger' with an address below in Banbury, Oxfordshire (UK), and a date of 13.11.1899 to the bottom of the page. Backstrip mostly detached from text block with lots of leaves loose in the binding, and also with several other loose bits of paper inserted between leaves. Text block toned throughout but generally without foxing. Book manufacturer stamp to rear pastedown of William Fullford, London.
