The sun., 1896-09-06
4 PTOTOGRAPHIC LIBRARI.
ProG Fessenden's Method OF Putting sc. .0Oo
Volumes Into n Small BOX.

Prof. Reginald \. Fessenden of Pennsyl-
van!a says that It is possible TO condense a
library of $4,000 volumes into a box of one
cubic foot capacity by means OF photography
Prof. Fesscnden has used photography for
several years in collecting scientific data and
has found not only that this method is che aper
than the cost OF paper on which to write the
same amount Of matter. hut also that il occu-
pies only per cent. OF the time required in
copying by hand. From the results that he
has obtained in this way he thinks that II Is
not impractIcable to reduce IA tig reference
library to small bulk by the same method.
Prof. FcsscHdcn says In the Electrical World
rs an illustratinn Of what might be accom-
plishcd hy photography, that 1t would be an
extremely easy matter, for instance. 10 ar
range the mechanism OF a plate containing n
German dictionary so that by the pressure OF a
couple Of keys the pace commencing with any
given letter could he thrown on the screen.
Prof Fessenden says he has overcome tho
difilCulticl arising from the necessity of accu.
rn;e focusing; the expense q the plates, and the
!s employed. 3avins an ii Incl focus, 'If' and a
te shnie" Journal. The psrer Is iaid 'sT On the he
pended Oh n bracket above the desk. is focused
soas to include the page. \ plate holder is
thon put into The camera and exposed for ten
seconds. II the illumination comes from q stu.
aent lamp OF 3" candle power. placed on the
desk opposite the paper, and onetenth second
holder IL then put away until a convenient 90.
portunity occurs for developing. From the
the Time the is s" Ssh. q" "fts II need Hn, no
he more than twenty seconds When twenty.
five or thirty plates arc exposed. which may
3c within a week or so. they are all put In one
tray and develoned together. As all have made
the same exposure 1t is not necessary &c watch
lie developed. liked. and left to wash in ten
minutes; The whole time spent in copyinu
one article or table. Including prepnratI.n for
washing filing away, and labelling is less than
one minute, according to the Professors expert
small envelopes stuck to the hncks Of paste.
board cnrd.; These plates used are only III
inches hy li6 inches. and can hold upon tbem
1000 words, SO that each word can he easily
read With u small mHgnitying glass This
whc MgI I'M .o% w SSs Of ssssFyng
preventing errors In copying. In case one does
not wish to copy more Than 400 or 800 words
son OF average evcsight without the use of a
glass. SO convenient is this method that Prof
FesSenden states ho uses it for copying all his
The success Of this method" says the Eltc
trtcdl bmm, has caused the writer TO in
dulEe In some speculation as to the possibility
OF an extended use OF the Photographic method
for publishing books, The last number OF the
reading matter of 1000 words each. The pho.
tographic plate ono inch square would contain
HS"at % yasrs Ss seanS "r 5 "r yane Of hs a
the annual report of the transactions OF the
Institute Of Electrical Engineers. This is al
most inccncoiyable. for 900 volumes OF thou
sand pages each is n fair sized library. The
only thing that TIL recently stood in the w.v
of its practicability t. e, the coarseness OF the
grain OF ordinary Photographic plates. has been
removed by Lippmann IN the beautiful ex-
leighs proposed method OF TAX Ing colored photo
graphs by Interference methods an accom-
plshed fact. Even with II magnifcation OF
thirty dlameters instead of the 900. which have
assumed, one such volume would go on a plato
one inch square. AT this rate box one foot
or 100000 with the larger magnihcation.
However startling this may SEEM Il is not i'm
practicable. at least, for the lower power
mentioned. and II is well within thu bounds Of
future will do his book work with the aid OF a
small projection lantern, and library. OF
Of the price now paid. The thing e Infinite.
Is more practical than the proposition. sorl-
ously made and received, Thai phonograpil
cylinders should take the place OF books. II
rate OF l50 words per minute for ten hours per
day, to utter tho words which may be con.
tanned on a piece Of glass ono inch square,
ulAr part OF work. there u no Comparison"