The Act of 1801 contained an important clause (clause 5) of general application, providing that the Postmasters-General might at discretion undertake the conveyance and delivery of letters "directed to persons abiding in towns, villages, and places (not being post-towns)," for such sums as might be agreed upon between the Postmasters-General and the inhabitants. Under this provision it was found possible to extend the service to a considerable number of places.[546] An Act of 1805[547] imposed an additional charge of 1d., making 3d. in all, on letters sent by the twopenny post and not passing by the General Post, directed to or sent from places beyond the limits of the General Post delivery; and on every letter passing by the General Post and directed to places beyond the limits of the General Post delivery, and delivered by the twopenny post, an additional charge of 2d.[548] There were now, in reality, two local posts in the London area--the twopenny post, for letters transmitted between places within the limits of the delivery of the General Post; and the threepenny post, for letters directed to or sent from places within the limits of the local service, but beyond the limits of the General Post delivery. In 1831 the limits of delivery of the twopenny post were extended to include all places within a radius of 3 miles of the General Post Office; and in 1833 the limits of the threepenny post were extended to include all places beyond the 3-mile limit, and not exceeding 12 miles from the General Post Office.[549] No further modifications of importance were made before the establishment of uniform penny postage. The introduction of a uniform rate of postage for the whole country of 1d., only half the lowest rate which had been charged in the London local post, obviously made unnecessary the continuance of that post, and also of the penny posts scattered up and down the country; or rather extended to the whole country the benefit of rates based on items of local cost only, since the system of uniform postage irrespective of distance rests on the recognition of the preponderating cost of the local or terminal services, and the relatively insignificant cost per letter of the service--conveyance from place to place--which depends on the distance of transmission. Financially the London penny and twopenny posts were always successful. Under the penny rate the profits had approached half the gross receipts--in 1800 they were 43 per cent.--and under the twopenny rate at once rose to more than 60 per cent., in 1825 reaching 67 per cent. The net revenue, which in 1801 under the penny rate was £16,286, had in 1837 under the twopenny rate risen to £73,334.[550] CANADA