Born and educated in Germany, moved to London in 1850; worked in workshop of optician W Hewitt and then of Andrew Ross; eventually appointed scientific adviser to the firm and entrusted with the testing and finishing of the finest optical apparatus; married Ross' second daughter Hannah in 1854; Ross died in 1859 and Dallmeyer inherited a third of Ross' fortune and the telescope manufacturing part of his business; Dallmeyer produced telescope, microscope camera and magic lantern lenses; remarried in 1862; passed business on to his eldest son Thomas Rudolphus Dallmeyer in 1880 due to ill health; lost overboard and presumed drowned on a cruiise off New Zealand, 30 December 1883.