It may here be noticed that, although the postmasters-general were under obligation to supply horses on demand, and, failing to do so, became liable to a penalty, the control which they exercised over the travelling post appears to have been of the slightest. It is true that they would now and again complain of a postmaster for keeping bad horses; but the badness would always be with reference to the horses' capacity to carry the mails. Whether they were fit or unfit for the use of travellers appears never to have troubled headquarters. Except, indeed, for some little exertion of authority on rare occasions and in circumstances out of the common,[38] it would almost seem that the postmasters-general had ceased to regard the travelling post as a matter in which they had any concern. It is not very clear why this should have been so. But perhaps the explanation is that in the case of the travelling post, unlike that of the letter post, a postmaster's interest and duty were identical; if horses were wanted, he was under the strongest inducement to supply them; and the danger to be apprehended was not that travellers would be neglected, but that they might be accommodated at the expense of the mails. [38] The following letter affords an instance of the exertion of authority referred to in the text:-- To the DEPUTIES between LONDON and TINMOUTH. GENERAL POST OFFICE, _April 6, 1708_. GENTLEMEN--The bearer hereof, Mr. John Farra, being directed by order of the Lord High Treasurer to proceed to Tinmouth on the publick affairs of the Government, I am ordered by the postmasters-general to require you to furnish the said gentleman with a single horse [_i.e._ a horse without a guide] if required through your several stages, he being well acquainted with the roads and coming recommended by such authority, which by their order is signified by, Gentlemen, your most humble servant, B. WATERHOUSE, _Secretary_.