An Examination of some Tolles Microscope Objectives and theAperture Controversy with Wenham

摘要

When water-immersion objectives came into use in the 1870s a heated controversy arose over their effective apertures. The apertures claimed by Tolles and his supporters were disputed by Wenham on the evidence of his measurements. Analysis of a surviving Tolles lens and contemporary data sheds new light on the controversy and shows that both had some justification for their claims.