It was into the port of London that ship letters chiefly came, and here the number which found their way to the Post Office in Lombard Street was seriously affected by the establishment of the penny post. That this was only natural will appear from a simple illustration. From Marseilles to London the postage was 1s. for a single letter. On one hundred such letters, therefore, the charge would be £5. But if, instead of taking these hundred letters to the General Post Office, a shipmaster on his arrival in the Pool dropped them into the penny post, they would all be delivered for 8s. 4d. It is true that he would thus lose his gratuity of one penny a letter; but the difference between the two rates of postage was such as to leave an ample margin of profit, even after making him full--and more than full--compensation for his loss. Indeed, if he had been bent on cheating his employer as well as the Post Office, he might with very little risk of detection have put the whole of the difference into his own pocket. In 1686 the number of ship letters accounted for to the Post Office was 60,447,[20] a number which, forming as it did the basis of a payment, may be taken as absolutely correct, because the Post Office would take good care not to pay more, and shipmasters not to receive less, than was absolutely due. It is to be regretted that no similar account is forthcoming for previous years, so that it might be seen what was the extent of the influence which the penny post exercised; but that this influence was considerable is certain from the continual references made to it by successive postmasters-general during a long series of years. It is to be observed, however, that they always speak of it as a thing that was past and gone, a thing baneful enough while it lasted, but as having been of only short duration. The explanation is no doubt to be found in the fact that in 1696 two officers were appointed, whose duty it was to collect letters from all vessels arriving in the port of London. The boat employed in this service had assigned to it special colours of its own, on which was depicted a man on horseback blowing a post horn.[21] [20] "To divers Masters of Shipps for 60447 letters by them brought from forreigne parts this year at one penny each according to the usage--£251:17:3."--Extract from writ of Privy Seal for passing the accounts of "our Right Trusty and Right well-beloved Couzen and Councellor Lawrence Earle of Rochester, Late our High Treasurer of England."