, 1874-05-16
THE HELf0TYPE PROCESS
What It Is, and What It Doaa


| tion u tne dellotype process. Doubtless M,
shrevdly fancied thai mere fetch, good enor
for prete1t, but really no reason Ut all ~
~ the process was then known to tho puh},, ;.
had only copied few OF the older .at -
points in tho s'Gray Collection OF En,.av;n,.s :
at Harvard, and made illustrations for -
| books publshad By Osgoo i Co. The e.r.'.'
public knows little more OF 1t to-day, and h,,.4
anybody outside Of 3 small circle in p5a,o, !:
aware Of the large proportions which the pro-,'.
has attained, Of the manifold applications III.
are nade Of it, and OF the almost unlimited ,,na.
OF its possible applications in tha seryica NJ ~
art, and in the promotion OF business.ints,s.."
Yet it occupies tho whole upper door of 1,-.s
building room containing II 200 squs,a ,as..
twonty-nine presses are now busy in s1rr, -
fill the accumulating orders, and fourteen ,,,.
ni1 soon be added Surely, this means has,r..,
WHAT II THE uELlorYPE PEocEss,
1t can be fully understood only by ssetn, r.
get description may give soma iaea Of il,
scientific principle on which it il based, .ndo.
the mode in which tho principle is applied.
The principle on which tho Heio.spe p.oe,u.
based was discovered BY u. Poiteuu, 4 Frtncsa.ls
more than twenty years ago; :; bCt the scrk;nr. ~.
~ descFibtd BY hun ~@s not found to i 2srci.s;
Various notifications have been sugge.tsd from H..
to tune with mora or less SUCCESS. In tha H.:
Irocess, beyond tie actual principle, eycrY rsg5p
peculiar to itself, and has haeu prosctel uT n..
Tn principle above refersel to IS, tia. s:I.as'>
which ordinarily absorbs water very readily ret ~,
tfeatsd vita bichromAts aud e1Eos<d % Il. ,-s.
Vi light, loses THU Property 10 gse4ter Or las. d.
according AZ tbs 7rticn Of the gus Ii grezter or -
So that We can produce by Light on snee. Of hetr'
mAtized geLtine, hJ meaus Of ordinary nnr
graphic negative, tbs Hame result that u protueS =
lihosrzphy BY drawing on a4teno with g-s1J b..
that Ii to say wnero ths light hzs acted just u ~,
the greasy lux haa been used, water i. rc1eed: al
whers light haa rsrtlJ acted, In tbs ha-ssasa of
negative. water is partly absorbed. Aua erezs. rsr1
rsvsled. Ordinary ge!atins Is di4sol,:d !
S,e11enate 81 potatsA il ADDED t to -esGes qGaasaH
aitse to light and Of alum to maks 1t vary hsrd II
durable. This il poured Oh lerel plata, pse.tocH
rubbed over with Max, and a dried BY nsana Of TX
ge!atins il stripped fiom the pt.ic and printed mi
Photograph: negative When thu p:rtu.s s2x -
sufficiently plainly the sucst Of Ce4tine is taktn
undsr ths negative, and made to adhere to usi
plate. Tas method Of adhesion used IL tn, /
atmospheric pressure. Ths sheet Of RelAoa ,ad :.
metal plsts ars put sogethes unasr water: a4s.
Of tha wxter ~ possible Is got nd Of fnoa b.
tween the two surfaces, the gelatins axa:a
the reminder, 50 thst vacuum IL Craatsd, .al
the picture IL thus attached 10 tbs plata By the ~
Of tue atmosphere. The superduous chemicals :,
soaked ous with w4ter, and the plate, with :hsEa&
ing surfsea Of ss atina attached, Is plsoed e Il
orain4ry platen pr1nting-prcss, and linked up ri.
orlinary photographic ink. As in nthogsaphy t !
necessary, after syery impression, to damp III .a
with water A mask Of pu2cr il used to zscn1. wa
margins for tbs prints and the impression tae
pulled, and is ready for issue. Two rnors :ab
ture, as 1t il found th.t, where the light hi, I'd
deeply, stiff ink Is required; but whess ns4
acted not so deeply,-th4t Is, in ths half-soHa,7
thinner ink may be used. So that stin ink kn5a:
for tho half-tonea In this manner three or fourth
may be used III printing one impression The G1
Of India OF other colosed tint il obtained BY psn
stead Of ordinary wafer for dampaoag the plate ~.
with sono co!or in It. Tic paler absorbs e4.x7
amount Of water out Of the plate and with It ern7
amount Of color. The ordinary rollers not tsna
to bs satisfactory; and mixture Of Qsiuc1x. gyts:<
iue, &nd c4sior-uii Il used.
The patent Of the aeliotype process beleas
to ]. r. Osgood l. Co.. but the operation ci 4
is under the uuperlntendenco Of nE; Ernest E
wards, = graduate Of Cambridge Unlverslty,:
England, and the inventor Of tie proccs. b
which u. Poitern's principle ia rendered x,Ir
able for practical use
One OF tho most successful applications 0. ia
Heliotypa process IL
THE REPRODUCTION, II PERFECT FAC-SIMILE
OF rare and costly engrayings. Ss7eral ;nclt:s
Roshorities OF HlrraTd. College for pablniics
Helotype copies Of the engray1nss in theta1ra4
"GE2y Collection" which il All s1ceec:a2i7
valuable collection, but virtually inaccessllaso
the public. It numbers about 5000 e2sssr1s.1
some Of them very rare aud costly, Ind IN.
cluues specimens Of every MASTER, and of
almost every Prodncs q tue s eo$EaTsr:: aa5:,i, ~
since its birth. OF course, vary many Of tn
t, ,000 are merely curious, and not worth repro
duc,u2; but perhaps 500 Of them are sttsssa
useful for purposes of art study, or are Of "a
popular . character, that it rilt pay 70 eoYf
taem. About 300 have been slready rnblIshsd;
among them, lnrge number by Albert Duts.
1ucluding his Life OF tno Virgin IN twenty pIs-'
tures; many by Rembrandt; charming po't:.
folio Of twenty-four frescoes OF Corre5g2 md
eugr.ved BY Toschi; aer:es q
French portraits By Nanteuil and Naaau;
William Blake's strikiug!y-onginal, no: tofI
ILLUSTRATORS OF tho Boo1 Of 1ee
n t~euty-two plates, aad numerous osasss
Titan, Carlo Dolci and S4Ivator Rosa. Anon5
hose in preparation are some Of this "ortt :
.amoua masterpieces Of Nurillo, T.tsn. 81 /
Joshua Reynolds, Leonardo Da Tiuci, Corra2ga !:
nd Raphael
l. would seem that there is hardly Insh :
he uss that may be made Of this process far
ILLUSTRATING BOOKS,
mt az ret not mora than dozcu have bec1s
Illustrated iu :ho country. Tao best kno*a T. +
tauces are Higgiuson's Oldport Days, Fl4s:i !;
Woods and BY-1TEys Of New England, D:Ais! !
Historic Fields aud Mansions OF Niddlcsel,
|Axe's proud Mlns 1lacBside," and soma OFFS
inest pictures in Whittler's " "Cnsld-Lfa
oroBs," and in Blackbnrn's "Hormandy fs
ureaauo" aud ':Artists snd Arabs" ,r-
Architects have been quick to zee how reada1 |
ns He1iotvpe process would loud itself to ses'e
heir interests. When oncs they have com?!s:a
design, c1act copies can be almost ln1tF
Ltely multiplied 10 any e1tent dedifed. 1es
architectural !Sketch-Dook, ,Esued monthly, eoa-
aims specimens Of ths finest work Of oaf ba'.