The Science observer code
Contributors: Ritchie, John, Jr
Series: Boston scientific society. Occasional publications. No.1
Publisher: Boston scientific society
Published: 1888
Place of publication: Boston
Language: eng
Subjects: Cipher and telegraph codes; Astronomy
Table of contents: title: -Pt. 1. Explanation of the number code, [by] S. C. Chandler, and J. Ritchie.-Pt. 1a. Number code, compiled by John Ritchie. 1885.-Pt.2 Phrase code, [by] S. C. Chandler, and J. Ritchie.-Pt. 3. Tables.