Geometrical pen:- made by H.Perigal

Perigal was an active member of London’s scientific societies during his long life. He had written on his gravestone: ‘A learned and ingenious geometrician, he investigated and illustrated the laws of compound circular motion.’ During the 1840s and 1850s he made many detailed drawings with this machine, which is a large and complex version of the geometric pen invented by Giambattista Suardi a century earlier. It can produce a vast range of cycloidal and epicycloidal curves combining the motion of the multiple gear wheels and offsets.