Tuesday August 21, 1894

A man called from Mess^rs Troughton & Simms about the Position of the 28 Inch Micrometer. I shewed him the method of illumination used in the Astrographic Telescope. He had been unable to obtain a dark field and illuminated wires in the way suggested by the Astronomer Royal, and wished to use some prisms to reflect the light. M^r Lewis & I discussed the matter with him and agreed that M^r Simms should do it as he liked & alter it subsequently, if necessary.

Frank Dyson, Chief Assistant