post road for towns on
another post road must therefore pass through London, and all letters
passing through London were subjected to an additional rate of
postage;[37] that is to say, they were charged the appropriate rate in
respect of the distance to London, and then, in addition, the
appropriate rate in respect of the distance from London to destination.

The Ordinance of 1657 placed the Post Office system for the first time
on a statutory basis.[38] The objects for which such an Office was
required were given as three in number: first, to maintain certain
intercourse of trade and commerce; secondly, to convey public
despatches; and thirdly, to discover and prevent many dangerous and
wicked designs against the peace and welfare of the Commonwealth. In
1660 an Act of Parliament was passed, dealing with the Post Office.[39]
Essentially it was the Ordinance of 1657, passed as an Act to give it
legal validity under the changed order of things. The clauses relating
to the use of the Post Office as a means of detecting plots against the
State were included in a modified form, and this function was by no
means lost sight of.[40] During the excitement caused by the Popish Plot
it was freely exercised.

The general farm of the posts was abolished in 1677, and the
administration of the Office undertaken by the Government, except in the
case of the smaller branch posts, in regard to which the practice of
farming was even extended in the early years of the eighteenth
century.[41]

The revenue yielded by the Office continued to expand. In 1694 it had
reached [L]60,000; and when, for various reasons, but chiefly to provide
for the control of the Post Office in Scotland, which had been brought
under the English authorities by the Act of Union, a new Post Office Act
became necessary, the Ministers, involved in a protracted war, seized
the opportunity to obtain an increased revenue from the Office. Under
William III this had been thought of.[42]

The Act of 1711,[43] which remained for over fifty years the principal
Act relating to the Post Office, was to be an instrument of taxation.
For some fifty years the Post Office had been yielding a revenue,
constant and increasing, but nevertheless more or less fortuitous. Its
functions had always been defined as primarily to provide for the
transmission of letters, for the benefit of commerce, and for the safety
and security of the kingdom, by bringing all letters into "one Post
Offi