Perhaps you should try some spelling variations:
early telegraph » mails telegraph, early typography, early tomography
delay telegraph » der telegraph, delay tomography, aerial telegraph
solar telegraph » global telegraph, postal telegraph, solar holography
der telegraphen » der telegraph, der telegraphie, und telegraphen

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: ((early telegraph) OR (((((delay telegraph) OR (solar telegraph))) OR (der telegraphen)))).
• Adding a wildcard symbol may retrieve word variants: ((early telegraph) or (((((delay telegraph) or (solar telegraph))) or (der telegraphen))))*.