Work at the Observatory.

Preparations are being made at the Observatory for photographing the nebula of the Nova Persei. Ever since the star was discovered last February it has been growing fainter, and it is feared that if photographs are not obtained soon no further chance will be offered. Every night telescopic photographs will be taken and the time of exposure will be lengthened, as it is thought that under-exposure may account for recent failures to obtain photographs of the nebula. It is intended also to determine by the parallax method the distance and motion of the star.

A shower of Leonids, similar to those of 1833 and 1866, is predicted for Thursday or Friday night. This is the last time they may be expected for thirty-three years, and ample preparations have been made at the Observatory to cover the entire field of the shower. Four cameras have been mounted on a platform moved by clockwork so that they will cover the same sixty degrees of the sky, throughout the entire shower. Six other instruments will be in use for determining the spectrum, magnitude and distance of the Leonids, and the radiant from which they come.

The telescope used by Professor Pickering in Jamaica last summer for a careful investigation of the moon, has recently been returned and is at present in use at the Observatory.