In 1892, on the Bristol Channel, he established communication between Lavernock Point and an island called Flat Holme in that channel by placing at these positions insulated single-wire circuits, earthed at both ends and laid as far as possible parallel to each other, the distance between them being 3.3 m.
The most famous comet is, of course, Halley's Comet, but there are other comets like Holme's and Hale-Bopp.