“ In woollen manufactures, “condensation” of the wool is an important operation and is accomplished by means of a “condenser.” The term is also given—generally as a qualification, e.g. condensing-syringe, condensing-pump,—to apparatus by which air or a vapour may be compressed. In optics a “condenser” is a lens, or system of lenses, which serves to concentrate or bring the luminous rays to a focus ”