Letter from H F [William Henry Fox] Talbot, Worthing, to 'dear Sir' [Henry Kater] Talbot has found his notes from Munich on [Joseph von] Fraunhofer's method of making object glasses. He does not consider this important, but relays a description of the process, including an integral sketch of the steel spherule and cup arrangement used to grind the glass. The largest and smallest lenses are not ground in that way. Glasses are polished using red oxide of iron throughout the full polishing process. Talbot also describes this, including the back-and-forth mechanical motion. Centering the object glass is done by attaching it to a small telescope, with the aid of three steel points, looking from the object glass to the eye glass. 8 February 1826