Page 27 - The Wellington photographic handbook

developer to produce a given type of negative is determined by
the temperature. With WELLINGTON 'Xtra Speedy Plates
and the Pyro-Soda Developer given on page
13, development is
complete in three minutes at a temperature of 70° Fahr., in three
and a half minutes at 65° Fahr., and in five minutes at 60° Fahr.
These times are subject to slight modification according to the
character of negative desired.
WELLINGTON Plates are admirably adapted for time
development in the tank. The following formula is recommended
:
PYRO-SODA.'
No. 1.
Pyrogallic Acid 1 ounce 50 grammes
Sodium Sulphite (cryst.) 2 ounces 100
Citric Acid 40 grains 4-5
Water to 1 0 ounces 500 c.c.
No. 2.
Sodium Sulphite (cryst.) 8 ounces 100 grammes
Sodium Carbonate (cryst.) 100
Water to 80 1 litre
The developer is made bv taking half an ounce (12-5 c.c.) of No
1 four
ounces (100 c.c.) of No. 2, 20 minims (or drops) of a 10% solution of
Potassium Bromide, and diluting to make 40 ounces
(1 litre).
TIME AND TEMPERATURE TABLE.
55°F. 60°F. 65°F. 70°F.
'XTREME Plate 35 29 25 21 minutes
'XTRA SPEEDY Plate 32 26 22 18
PRESS Plate 31 25 21 17
ANTI-SCREEN Plate ... 30 24 20 16
ISO SPEEDY Plate 30 24 20 16
SPEEDY PORTRAIT Plate 27 22 18 14
ORDINARY Plate 23 18 14 10
The following points require careful attention if plates are to
be developed successfully by this system.
The developer must be
made up accurately, as slight alterations in its composition may
considerably alter the time required.
The temperature should be
taken after mixing and immediately before
use. No attempt
must be made by the addition of hot or cold water to bring the
solution to any particular temperature, as such temperature will not
be maintained, unless it happens also to be the temperature of the
room. A thermometer, with its scale engraved on the stem or
enclosed in the glass, should be used, and should be left in the
* Before making up any formula, read the notes on pages 125, 126 and 134.
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