the principles pioneered by Archer were purchased and in 1854 the United Kingdom postal authorities started continuously issuing perforated postage stamps in the Penny Red and all subsequent designs. In the United States, the use of postage stamps caught on quickly and became more widespread when on 3 March 1851, the last day of its legislative session, Congress passed the Act of March 3, 1851 (An Act to reduce and modify the Rates of Postage in the United States). Similarly introduced on the last day of the Congressional session four years later, the Act of March 3, 1855 required the prepayment of postage on all mailings. Thereafter, postage stamp use in the United States quickly doubled, and by 1861 had quadrupled. In 1856, under the direction of Postmaster General James Campbell, Toppan and Carpenter, (commissioned by the United States government to print United States postage stamps through the 1850s) purchased a rotary machine designed to separate stamps, patented in England in 1854 by William and Henry Bemrose, who were printers in Derby, England. The original machine cut slits into the paper rather than punching holes, but the machine was soon modified. The first stamp issue to be officially perforated, the 3-cent George Washington, was issued by the United States Post Office on 24 February 1857. Between 1857 and 1861, all stamps originally issued between 1851 and 1856 were reissued with perforations. Initial capacity was insufficient to perforate all stamps printed, thus perforated issues used between February and July 1857 are scarce and quite valuable. Shapes and materials In addition to the most common rectangular shape, stamps have been issued in geometric (circular, triangular and pentagonal) and irregular shapes. The United States issued its first circular stamp in 2000 as a hologram of the Earth. Sierra Leone and Tonga have issued stamps in the shapes of fruit. Stamps that are printed on sheets are generally separated by perforations, though, more recently, with the advent of gummed stamps that do not have to be moistened prior to affixing them, designs can incorporate smooth edges (although a purely decorative perforated edge is often present). Stamps are most commonly made from paper designed specifically for them, and are printed in sheets, rolls, or small booklets. Less commonly, postage stamps are made of materials other than paper, such as embossed foil (sometimes of gold). Switzerland made a stamp that contained a bit of lace and