In the past 35 years the Office for Monuments & Archaeology (Bureau Monumenten & Archeologie; BMA) has found over 2000 objects made from hard animal tissues. These objects are found in excavations from all over Amsterdam and are dated between the 12th and the 19th centuries. The materials that were identified are bone, antler, ivory, horn, tortoise shell, baleen and hoof. These materials were used to manufacture objects with different functions, such as toys, combs, toothbrushes, beads, buttons, needles and many more (Rijkelijkhuizen 2004). The finds of five bone telescopes are unique in Dutch archaeology.