Perhaps you should try some spelling variations:
"mails telegraph" » "marine telegraph", "cable telegraphy", "mining telegraph"
"early telegraph" » "early typography", "early tomography", "marine telegraph"
"mayo telegraph" » "a telegraph", "random telegraph", "marine 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 ("early telegraph"))) OR ("mayo telegraph")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"mails telegraph\") OR (\"early telegraph\"))) or (\"mayo telegraph\"))".
• Removing quotes may allow a broader search: (((( mails telegraph ) OR ( early telegraph ))) or ( mayo telegraph )).
• Adding a wildcard symbol may retrieve word variants: (((("mails telegraph") OR ("early telegraph"))) or ("mayo telegraph"))*.