Little more than half a century had elapsed since the introduction of postage, and meanwhile the revenue had risen by strides which were for those times prodigious. In 1635 the posts were maintained at a cost to the Crown of £3400 a year. Within fifteen years not only had they become self-supporting, but a rent was paid for the privilege of farming them. This rent was, in 1650, £5000 a year; in 1653, £10,000; in 1660, £21,500; and some time before 1680, £43,000. In 1690 the net revenue was probably about £55,000. In 1694, according to a return made to the House of Commons two years later, it was £59,972. The headquarters of the Post Office were at this time in Lombard Street. Here the postmasters-general resided; and here, far from shutting themselves up, they were to be found at all hours by any one who might wish to consult them on business connected with their office. Freedom of communication with those among whom they lived, and not inaccessibility, appears indeed to have been a part of their policy. With the foreign merchants especially they maintained the most friendly intercourse, and were wont to defer to their wishes and suggestions in the arrangement of the packets. Besides giving constant attendance during the day, the postmasters-general sat as a Board every morning and night. To these Board-meetings they attached the highest importance, especially on the nights of Tuesdays, Thursdays, and Saturdays, when mails were despatched into all parts of the country. These were known as the "Grand Post Nights," and the others as "Bye-Nights." The Post Office building appears to have been not ill adapted to its purpose. A massive gate opened into a court of oblong shape. This court was paved from end to end for the merchants to walk in while waiting to receive their letters. On the right was the Board-room with the residence of the postmasters-general attached; on the left the office for foreign letters; and in front, immediately facing the entrance, was the sorting office. The office for the letter-carriers was in the basement. The rest of the building was devoted to the use of the Post Office servants, who, owing to their unseasonable hours of attendance, were required to live in the office itself or else in its immediate vicinity.