mechanically, not by hand, there was no variation 
between them. The questionable devices for stretch- 
ing the output of each worn plate were avoided, 
for there was an endless supply of fresh plates. It 
was feasible once more to employ only the most 
skilled of engravers to make the original engraving. 
By repeating high-class engraving several times on 
the plate, combining this with complex machine- 
engraved patterns, and reversing the blacks and 
whites in parts of the design, a composite plate could 
be built up which was well beyond the copying skill 
of the ordinary engraver. 
Perkins’ siderography was already well tried before 
he submitted it to the Bank Committee in 1818. 
He had worked it out in America over the previous 
By 1804 
the developing process already involved the transfer 
twenty years, from a much simpler idea. 
by pressure to mild steel and subsequent hardening 
of the steel. It was adopted at its different stages by a 
In 1810 the 
process was patented in England" and demonstrated, 
considerable number of American banks. 
unsuccessfully, to the Bank of England on Perkins’ 
behalf by his agent, J. C. Dyer.!* The process in its 
perfected form of 1818 was undoubtedly the most 
important suggestion that was made to the Bank, and 
it was short-listed with the Applegath and Cowper 
process for the final choice. William Congreve, 
however, was determined to oppose the American 
Perkins 
and his friends believed that Congreve’s hostility 
In December 1819 Perkins 
plan and to further his own at the same time. 
had caused their failure. 
wrote to a friend: 
We were told yesterday from the best authority that one 
of Sir Willm. Congreave’s workman had said, that Sir 
Wilm. had been as cross as a bear, ever since our 
specimens were exhibited to the commissioners, that he 
had said that he expected the American plan would be 
adopted, altho it was not any better than fvs own.!8 
According to an Irish banker, Thomas Joplin, Con- 
greve behaved as though: 
the competition lay between Messrs. Perkins and Heath 
and himself; and he wrote a pamphlet to prove that his 
plan was a good plan, and theirs good for nothing.!* 
1 J. C. Dyer, British patent 3385 (1810). 
2 A. D. MackeEnzik, op. cit. (footnote 1), p. 56. 
8 From a letter quoted in G. & D. Bathe’s Jacob Perkins 
(Philadelphia: Historical Society of Pennsylvania, 1943), p. 81. 
4T. Jopyin, An essay on the general principles and present 
practice of banking in England and Scotland, 6th ed. (London, 1827), 
p. 118. 
The full title of this pamphlet of Congreve’s explains 
his thesis: 
An analysis of the true principles of security against 
forgery; exemplified by an enquiry into the sufficiency 
of the American plan for a new bank note; with imita- 
tions of the most difficult specimens of those bank notes 
made by ordinary means, by which it is proved that there 
is no adequate security to be achieved in one colour, in 
the present state of the arts, and that the true basis of 
security is in the due application of relief engraving, and 
printing in two or more colours, 
A copy of this rare pamphlet is in the Patent Office 
Library in London. Ten of its twelve pages of 
illustrations are imitations of Perkins’ siderographic 
notes or parts of them. One shows a clumsily en- 
graved and printed compound plate and one is a 
very beautiful specimen of Congreve’s ‘triple paper.” 
The siderography were the work of 
Congreve’s friend Robert Branston, and Branston’s 
son. Robert Branston was one of the greatest English 
wood engravers of the time and a leader of the 
London school of engravers, the rival to Thomas 
Bewick’s pioneer school in Newcastle. 
imitations 
The Perkins claim for siderography rested on the 
fact that it was virtually impossible to make by hand a 
number of identical engravings like the repeated de- 
signs on his notes. A forgery would give itself away 
immediately by the slightest variation between the 
designs. Branston got around this difficulty in a very 
simple way. He engraved only one copy of each 
design and printed this onto the paper as many 
times as necessary. Thus a note which, in the 
original, was composed of five designs appearing 
nineteen times altogether was copied by making five 
engravings and putting the paper through the press 
Branston engraved on 
wood and on metal, and used both intaglio and relief 
A trained eye could spot that 
his copies were printed part relief and part intaglio, 
as many as nineteen times. 
methods of printing. 
but the man in the street would notice only that the 
Bran- 
ston’s method was ingenious and his results were 
repeated designs were the same, line for line. 
remarkable, but there were serious weaknesses to his 
case. 
of so many impressions. 
No ordinary paper could take the punishment 
Branston pointed out that 
the relief blocks could be duplicated and united into 
one block by stereotyping, to reduce the number of 
But the task of making and printing the 
blocks was so great that it would have been easier 
and more profitable for the forger to earn a living as 
an honest engraver. 
impressions. 
Perkins and his company re- 
82 BULLETIN 252: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY 
