Improvements in apparatus employed in wireless telegraphy
A British patent specification from 1899 by Guglielmo Marconi and his Wireless Telegraph Company, printed for the Patent Office, describing apparatus for wireless telegraphy. Its single plate shows technical drawings for designers wanting raw engineering linework: a boxed electrical component at top, a long vertical rod with spheres and coils, and a wavy sine-like trace at the bottom, all in fine black ink on a cream ground.
