W. P. Gerrish, an assistant in the Observatory, has recently devised a system and code for use in the transmission of astronomical or other numerical data by telegraph. Since 1883 the University Observatory has been the official centre in the United States for the distribution of astronomical information; and the new system is the result of the experience gained during that period. A practical trial of it, conducted between Cambridge and Mt. Hamilton, California, developed no errors which could not be easily rectified.

Some of the advantages of Mr. Gerrish's system are its simplicity, the translation of numbers to and from the code without the use of a code book, and the possibility of detecting and correcting errors by inspection. The code itself is in reality a language of eleven words, each of which is a monosyllable of two letters. The series represents the ten digits with an eleventh character. In these monosyllables any one consonant is invariably associated with the same vowel and is never used in any other connection. The two letters thus form a combination which affords a means of locating and correcting all telegraphic mistakes; for, if one letter is known, the one going with it can be at once found.

A pamphlet describing the system and illustrating its use has just been published by the Observatory.