Handbook for translators of Spanish historical ... - University Library

HANDBOOK FOR TRANSLATORS OF SPANISH HISTORICAL DOCUMENTS
2. Hanau filter transmits ultra-violet similar to that
of Corning No. 587.
3. Wratten filter No. 18A. Transmits ultra-violet similar
to that of Corning Filter No. 587.25
When photographing documents under ultra-violet illumination,
it is often advisable to cause increased fluorescence
in order to make indistinct handwriting readable. According
to experiments made by R. B. Haselden, San Marino,
California, anthracene (Ci^H^q) > which is perfectly harmless,
when applied to paper, causes it to fluoresce strongly. 26
Anthracene solution is applied to the reverse side of the
paper with a soft camel-hair "brush. Vhen the alcohol in
the solution has evaporated, it leaves the anthracene in
a crystalline solution. When the ultra-violet light is
thrown upon the paper, it causes the whole leaf to fluoresce.
The previously invisible ink, however, obstructs
the fluorescence of the portion of the paper where it
rests, thus making the handwriting visible to the photographic
camera. 27
According to L. Bendikson, Henry E. Huntington Library,
San Marino, California, writing obliterated by ink stains,
of the same ink, may be made legible by making a photostatic
print, either from the original or from a photostatic
negative, of the ink-stained material through a
Wratten-Wainwright G-filter, under ordinary conditions.
This process usually cannot be successfully applied to
manuscripts that have certain lines purposely obliterated. 28
The same writer further states that in the case of superimposed
corrections sometimes infra-red rays may be successfully
used. By the use of infra-red radiation, it is
sometimes possible to exclude the entire visible spectrum
through the use of a Wratten-Wainwright infra-red filter
^^This information was taken from E. B. Haselden, Scientific
Aids for the Study of Manuscripts, p. 40. (The
filters listed under No. 1 are manufactured "by the
Corning Glass Company, Corning, N. Y. ; No. 2, "by the
Hanovia Chemical A Manufacturing Company, Newark, N.J.;
No. 3, "by the Eastman Kodak Company).
^^R. B. Haselden, Ibid. ,
27iMd_.
pp.
64-65.
L. Bendikson, "Phototechnical Problems: Some Results
Obtained at the Huntington Library," The Library Journal,
Vol. 57, pp. 789-790. -20-