as mortar while the Romans furthered mortar development by mixing lime with volcanic ash and sand. This material, known as pozzolanic cement, was used in the construction of the Roman Colosseum and Pantheon. The Romans were also the first people known to have used tar and beeswax as caulk and sealant between the wooden planks of their boats and ships. In Central Asia, the rise of the Mongols in approximately AD 1000 can be partially attributed to the good range and power of the bows of Genghis Khan's hordes. These bows were made of a bamboo core, with horn on the belly (facing towards the archer) and sinew on the back, bound together with animal glue. In Europe, glue fell into disuse until the period AD 1500–1700. At this time, world-renowned cabinet and furniture makers such as Thomas Chippendale and Duncan Phyfe began to use adhesives to hold their products together. In 1690, the first commercial glue plant was established in The Netherlands. This plant produced glues from animal hides. In 1750, the first British glue patent was issued for fish glue. The following decades of the next century witnessed the manufacture of casein glues in German and Swiss factories. In 1876, the first U.S. patent (number 183,024) was issued to the Ross brothers for the production of casein glue. The first U.S. postage stamps used starch-based adhesives when issued in 1847. The first US patent (number 61,991) on dextrin (a starch derivative) adhesive was issued in 1867. Natural rubber was first used as material for adhesives starting in 1830, which marked the starting point of the modern adhesive. In 1862, a British patent (number 3288) was issued for the plating of metal with brass by electrodeposition to obtain a stronger bond to rubber. The development of the automobile and the need for rubber shock mounts required stronger and more durable bonds of rubber and metal. This spurred the development of cyclized rubber treated in strong acids. By 1927, this process was used to produce solvent-based thermoplastic rubber cements for metal to rubber bonding. Natural rubber-based sticky adhesives were first used on a backing by Henry Day (US Patent 3,965) in 1845. Later these kinds of adhesives were used in cloth backed surgical and electric tapes. By 1925, the pressure-sensitive tape industry was born. Today, sticky notes, Scotch Tape, and other tapes are examples of pressure-sensitive adhesives (PSA). A key