DE LA RUE, Warren. 18062



Autograph Correspondence Card Signed, to Mr. Howletts, confirming that he has written to the President. Card 4 x 5 inches, in good condition. 73 Portland Place, 6 May 1886. Warren de la Rue (1815–1889), chemist and astronomer, invented the first envelope-making machine (1851); took lunar photographs; devised heliograph for photographing the sun daily (1858). By photographs of the eclipse of the sun in Spain, De La Rue proved that the prominences observed during eclipses belong to the sun (1860).