Perhaps you should try some spelling variations:
"mining telegraph" » "marine telegraph", "mining graph", "indian telegraph"
"mails telegraph" » "marine telegraph", "early telegraph", "cable telegraphy"
"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 ("mining telegraph"))) OR ("mayo telegraph")).
• Removing quotes may allow a broader search: (((( mails telegraph ) or ( mining telegraph ))) or ( mayo telegraph )).
• Adding a wildcard symbol may retrieve word variants: (((("mails telegraph") or ("mining telegraph"))) or ("mayo telegraph"))*.