IV INTRODUCTION 



Special credit is due Commander Myron J. Walker, U. S. N. (Ret.), 

 under whose direction the above work was accomplished, for his en- 

 couragement and assistance in the preparation of this text, and for his 

 efforts in bringing it to the attention of the Navy Department by whom 

 it was subsequently approved. Acknowledgement is due the compass 

 officers and technicians of the Bureau of Ships and the Hydrographic 

 Office who were very cooperative and helpful in reviewing the subject 

 material. The authors are also grateful for the helpful suggestions 

 made by the compass adjusters of the various naval districts. 



Nte S. Spencer 

 George F. Ktjcera 



