Perhaps you should try some spelling variations:
"cable telegraphy" » "all telegraphs", "early telegraph", "le telegraphe"
"mails telegraph" » "marine telegraph", "early telegraph", "mayo telegraph"
"a telegraph" » "a telegraphe", "_ telegraph", "2 telegraph"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("mails telegraph") OR ("cable telegraphy"))) OR ("a telegraph")).
• Removing quotes may allow a broader search: (((( mails telegraph ) or ( cable telegraphy ))) or ( a telegraph )).
• Adding a wildcard symbol may retrieve word variants: (((("mails telegraph") or ("cable telegraphy"))) or ("a telegraph"))*.