Photographing Unseen Stars

1895

One of the most popular and eminent lecturers on astronomy is Sir Robert Ball, who uses simple and graphic illustrations to give his hearers ideas of magnitude and distance. For instance, he says that going at the rate of the electric telegraph — that is, 186,000 miles a second — it would take 78 years to telegraph a message to the most distant telescopic stars, but the camera has revealed stars far more distant than these, some of which, if a message had been sent in the year A. D. 1 — that is to say, 1,894 years ago — the message would only just have reached some of them and would be still on the way to others, going at the rate of 186,000 miles a second.