This small portable magnifying glass from Ottway& Co is an extraordinary device that is only 3 cm high and 2 cm in diameter. It has two lenses of different magnifications and a 3 cm nickel-plated handle to allow its handling. One lens is graduated to a 10 scale and the other to a 100 scale.
All of it is housed in a tiny 6x4x3 cm box. It is a luxurious device and one of the smallest simple microscopes ever made. A similar model is number 31 of this collection.