I was present on one occasion at a popular lecture delivered in Greenwich, when the lecturer referred to the way in which so many English people travel to the ends of the earth in order to see interesting or wonderful places, and yet entirely neglect places of at least equal importance in their own land. 'Ten minutes' walk from this hall,' he said, 'is Greenwich Observatory, the most famous observatory in the world. Most of you see it every day of your lives, and yet I dare say that not one in a hundred of you has ever been inside.'

Whether the lecturer was justified in the general scope of his stricture or not, the particular instance he selected was certainly unfortunate. It was not the fault of the majority of his audience that they had not entered Greenwich Observatory, since the regulations by which it is governed forbade them doing so. These rules are none too stringent, for the efficiency of the institution would certainly suffer if it were made a 'show' place, like a picture gallery or museum. The work carried on therein is too continuous and important to allow of interruption by daily streams of sightseers.

To those who may at some time or other visit the Observatory it may be of interest to have at hand a short account of its history, principal instruments, and work. To the far greater number who will never be able to enter it, but who yet feel an interest in it, I would trust that this little book may prove some sort of a substitute for a personal visit.

I would wish to take this opportunity of thanking the Astronomer Royal for his kind permission to reproduce some of the astronomical photographs taken at the Observatory and to photograph the domes and instruments. I would also express my thanks to Miss Airy, for permission to reproduce the photograph of Sir G. B. Airy; to Mr. J. Nevil Maskelyne, F.R.A.S., for the portrait of Dr. Maskelyne; to Mr. Bowyer, for procuring the portraits of Bliss and Pond; to Messrs. Edney and Lacey, for many photographs of the Royal Observatory; and to the Editor of Engineering, for permission to copy two engravings of the Astrographic telescope.

E. W. M.

Royal Observatory, Greenwich,
August, 1900.