Tests of watches and chronometers 

 - London  NPL         1951 
 - 14p  cm. 
<br/><br/> Appendix: 9-14P; WEEDED OUT 
<br/><br/><label>Standard No.: </label>187235 
<br/><br/><label>Source: </label> Reference Collections 
<br/><br/><label>Dewey Class. No.: </label>"a9917(F).N51, J1"