Photozincography
Encyclopedia
Photozincography, sometimes referred to as Heliozincography but essentially the same process, known commercially as zinco, is the photographic process developed by Sir Henry James
FRS (1803–1877) in the mid-nineteenth century.
This method enabled the accurate reproduction of images, manuscript text and outline engravings, which proved invaluable when originally used to create maps during the Ordnance Survey
of Great Britain during the 1850s, carried out by the government's Topographical Department, headed by Colonel Sir Henry James
from photographic negatives.
method (a solution of nitrocellulose
in ether or acetone on glass). Once the negative had been made, a sheet of thin tracing paper
was coated in a mixture of saturated potassium bichromate solution and gum water, and dried. This was then placed under the photographic negative and exposed to light for 2–3 minutes. The bichromate/gum mixture remained soluble on the parts of the tracing paper that were shielded from light by the opaque areas of the negative, allowing it to be removed, leaving an insoluble ‘positive’ image. This bichromate positive was then placed on a sheet of zinc covered in lithographic ink, and put through a printing press
three or four times. After removal of the paper, the zinc plate was washed in a tray of hot water (containing a small amount of gum), using a camel-hair brush to remove all the soluble bichromate combined with ink. What remained on the zinc plate was a perfect representation in ink of the original composition, by virtue of the ink binding to the insoluble potassium bichromate.
The main advantage and innovation of this process over lithography was the use of zinc plates rather than stone ones. Zinc plates were lighter and easier to transport, could produce more prints, and were far less brittle than the stone plates originally used. The use of zinc plates was also the origin of the name photozincography, which Sir Henry James claims to have invented.
, was overly complicated, time consuming and, due to the number of moving parts, inaccurate. While there was some concern that photography would distort the image, Sir Henry set out to explore the possibility of using photography, setting up a photography department at the Ordnance Survey in 1855 and also securing funds to build the "glasshouse", a photography building with an all glass roof to allow as much natural light in as possible for photography. The development and discovery of photozincography or zinco came about four years later, being first mentioned in Sir Henry's report to Parliament
in 1859.
While the Ordnance Survey's Directory General Henry James (Ordnance Survey)
claimed to have invented the process, a similar system of document copying had been developed in Australia. John Walter Osborne (1828–1902) developed a similar process for use in Australia and for the same reasons as Sir Henry, to avoid using the tracing system of the pantagraph. While developed at the same time Sir Henry’s process, however as Sir Henry explained to a representative of Mr. Osborne in the quote below, he publicized it first.
Sir Henry, despite being the person who oversaw and set up the photography department, was not the actual inventor. The head of the photography department at Southampton, Captain A. de. Scott, did much of the ground work and basic development on photozincography. Sir Henry did acknowledge the work of Captain A. de. Scott in the development and use of the system in the introduction to the photozincographied Domesday Book
. Despite this it was Sir Henry who gained most of the public attention through his pamphlet on photozincography. He was knighted in 1861 for services to science.
The use of photozincography at the Ordnance Survey was a great success, with Sir Henry claiming it saved over £2000 a year, from the invention of photo-zincography; the cost of producing a map of a rural district was reduced from 4 to 1 and maps of towns were reduced from 9 to 1. It was also claimed that up to 2000 or 3000 impressions could be taken from a single plate. Despite this, the process was not perfect: it did not reproduce a full colour picture, and until 1875 boys were employed to colour in the maps produced by this method. The process, while better than the pantagraph, still required a large amount of labour to prepare the zinc plates for pressing. However, photozincography began to be used fairly rapidly in Europe
. Sir Henry was even honoured by the Queen of Spain
. Though originally developed to reproduce maps, the process was eventually to be used on a whole series of manuscripts, to preserve them and make them more available to the public. This included a reproduction of the Domesday Book in 1861–64 and several volumes of historical manuscripts. Whilst the process of photo-zincography was invented mostly for use the Ordnance Survey, The Photographic News stated that the process could also be used in the Patent office and would save vast amounts of time and money. The use of photozincography began to decline in the 1880s as better methods of reproductions were made available and in the 1900s the glasshouse was pulled down to make way for new printing presses.
Henry James (Ordnance Survey)
Major General Sir Henry James FRS MRIA RE was the director-general of the Ordnance Survey, the British Government mapping agency, from 1854 to 1875. Sir Henry was described by the agency itself as "perhaps Ordnance Survey's most eccentric and egotistical Director General"...
FRS (1803–1877) in the mid-nineteenth century.
This method enabled the accurate reproduction of images, manuscript text and outline engravings, which proved invaluable when originally used to create maps during the Ordnance Survey
Ordnance Survey
Ordnance Survey , an executive agency and non-ministerial government department of the Government of the United Kingdom, is the national mapping agency for Great Britain, producing maps of Great Britain , and one of the world's largest producers of maps.The name reflects its creation together with...
of Great Britain during the 1850s, carried out by the government's Topographical Department, headed by Colonel Sir Henry James
Basis
The foundation of this method is the insolubility of bichromate of potash upon exposure to light, allowing the printing of images on to zincZinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
from photographic negatives.
Method
At this time, high-contrast negatives were made using the wet plate collodionCollodion
Collodion is a flammable, syrupy solution of pyroxylin in ether and alcohol. There are two basic types; flexible and non-flexible. The flexible type is often used as a surgical dressing or to hold dressings in place. When painted on the skin, collodion dries to form a flexible cellulose film...
method (a solution of nitrocellulose
Nitrocellulose
Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...
in ether or acetone on glass). Once the negative had been made, a sheet of thin tracing paper
Tracing paper
Tracing paper is a type of translucent paper. It is made by immersing uncut and unloaded paper of good quality in sulphuric acid for a few seconds. The acid converts some of the cellulose into amyloid form having a gelatinous and impermeable character. When the treated paper is thoroughly washed...
was coated in a mixture of saturated potassium bichromate solution and gum water, and dried. This was then placed under the photographic negative and exposed to light for 2–3 minutes. The bichromate/gum mixture remained soluble on the parts of the tracing paper that were shielded from light by the opaque areas of the negative, allowing it to be removed, leaving an insoluble ‘positive’ image. This bichromate positive was then placed on a sheet of zinc covered in lithographic ink, and put through a printing press
Printing press
A printing press is a device for applying pressure to an inked surface resting upon a print medium , thereby transferring the ink...
three or four times. After removal of the paper, the zinc plate was washed in a tray of hot water (containing a small amount of gum), using a camel-hair brush to remove all the soluble bichromate combined with ink. What remained on the zinc plate was a perfect representation in ink of the original composition, by virtue of the ink binding to the insoluble potassium bichromate.
The main advantage and innovation of this process over lithography was the use of zinc plates rather than stone ones. Zinc plates were lighter and easier to transport, could produce more prints, and were far less brittle than the stone plates originally used. The use of zinc plates was also the origin of the name photozincography, which Sir Henry James claims to have invented.
History
Zinco or photozincography developed at the Ordnance Survey out of a need to reduce large-scale maps more effectively. The original method using a pantographPantograph
A pantograph is a mechanical linkage connected in a special manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a second pen...
, was overly complicated, time consuming and, due to the number of moving parts, inaccurate. While there was some concern that photography would distort the image, Sir Henry set out to explore the possibility of using photography, setting up a photography department at the Ordnance Survey in 1855 and also securing funds to build the "glasshouse", a photography building with an all glass roof to allow as much natural light in as possible for photography. The development and discovery of photozincography or zinco came about four years later, being first mentioned in Sir Henry's report to Parliament
Parliament
A parliament is a legislature, especially in those countries whose system of government is based on the Westminster system modeled after that of the United Kingdom. The name is derived from the French , the action of parler : a parlement is a discussion. The term came to mean a meeting at which...
in 1859.
While the Ordnance Survey's Directory General Henry James (Ordnance Survey)
Henry James (Ordnance Survey)
Major General Sir Henry James FRS MRIA RE was the director-general of the Ordnance Survey, the British Government mapping agency, from 1854 to 1875. Sir Henry was described by the agency itself as "perhaps Ordnance Survey's most eccentric and egotistical Director General"...
claimed to have invented the process, a similar system of document copying had been developed in Australia. John Walter Osborne (1828–1902) developed a similar process for use in Australia and for the same reasons as Sir Henry, to avoid using the tracing system of the pantagraph. While developed at the same time Sir Henry’s process, however as Sir Henry explained to a representative of Mr. Osborne in the quote below, he publicized it first.
I therefore handed this gentleman a copy of my Report, and desired him to read the account given of our process at page 6 of that Report, and to examine the copy of the Deed bound up with it, and not to show me the description of Mr. Osborne's process if it was differed from ours. After reading it, he said at once it was the same process, and I then told him it was useless for him to attempt to take out a patent as my printed Report had everywhere been circulated
Sir Henry, despite being the person who oversaw and set up the photography department, was not the actual inventor. The head of the photography department at Southampton, Captain A. de. Scott, did much of the ground work and basic development on photozincography. Sir Henry did acknowledge the work of Captain A. de. Scott in the development and use of the system in the introduction to the photozincographied Domesday Book
Domesday Book
Domesday Book , now held at The National Archives, Kew, Richmond upon Thames in South West London, is the record of the great survey of much of England and parts of Wales completed in 1086...
. Despite this it was Sir Henry who gained most of the public attention through his pamphlet on photozincography. He was knighted in 1861 for services to science.
The use of photozincography at the Ordnance Survey was a great success, with Sir Henry claiming it saved over £2000 a year, from the invention of photo-zincography; the cost of producing a map of a rural district was reduced from 4 to 1 and maps of towns were reduced from 9 to 1. It was also claimed that up to 2000 or 3000 impressions could be taken from a single plate. Despite this, the process was not perfect: it did not reproduce a full colour picture, and until 1875 boys were employed to colour in the maps produced by this method. The process, while better than the pantagraph, still required a large amount of labour to prepare the zinc plates for pressing. However, photozincography began to be used fairly rapidly in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
. Sir Henry was even honoured by the Queen of Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
. Though originally developed to reproduce maps, the process was eventually to be used on a whole series of manuscripts, to preserve them and make them more available to the public. This included a reproduction of the Domesday Book in 1861–64 and several volumes of historical manuscripts. Whilst the process of photo-zincography was invented mostly for use the Ordnance Survey, The Photographic News stated that the process could also be used in the Patent office and would save vast amounts of time and money. The use of photozincography began to decline in the 1880s as better methods of reproductions were made available and in the 1900s the glasshouse was pulled down to make way for new printing presses.
See also
- Henry James (Ordnance Survey)Henry James (Ordnance Survey)Major General Sir Henry James FRS MRIA RE was the director-general of the Ordnance Survey, the British Government mapping agency, from 1854 to 1875. Sir Henry was described by the agency itself as "perhaps Ordnance Survey's most eccentric and egotistical Director General"...
- PhotographyPhotographyPhotography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
- Photozincography of the Domesday BookPhotozincography of the Domesday BookIn the 1860s the first facsimile of the Domesday Book was created by the process of photozincography , and was executed under the directorship of Henry James at the Southampton offices of the Ordnance Survey.-Initial stages:...
- Gum bichromateGum bichromateGum bichromate is a 19th century photographic printing process based on the light sensitivity of dichromates. It is capable of rendering painterly images from photographic negatives. Gum printing is traditionally a multi-layered printing process, but satisfactory results may be obtained from a...