Ключевые слова: antique, closeup, cogwheel, drive, engineering, equipment, force, gear, gearing, gears, grey, historic, historical, industrial, industry, iron, isolated, machine, machinery, mechanical, mechanics, mechanism, mechanisms, metal, observatory, old, optic, optical, part, power, precision, quality control, reduction, refractor, robust, shaft, sience, sky, spring, steel, sturdy, support, technical, technology, telescope, university, wheel, workplace, workshop, worm,