The world's smallest electric motor weighing 0.37 grammes and consisting of 31 parts has been constructed by Yuri Yeremin a student of the Moscow Institute for Non-Ferrous Metals The motor which took ten days to build can be worked by a four volt pocket battery or by the city's electric supply passed through a bell transformer The diameter of the structure is 4mm the compound winding consists of 250 wire windings and the armature has 390 windings of the same wire 0.05mm in diameter Magnetic parts of the motor are made of tin the current-carrying portions of brass and all insulating materials and pulleys of ebonite Photo shows the miniature electric motor on the fingernail of Yuri Yeremin the constructor July 3rd 1935