The Heckelphone is a double reed pipe instrument similar to the oboe but pitched an octave lower as the diameter of the pipe (its bore) is larger than that of the oboe. In orchestras it is often used in the bass section of oboes. It has a bulbous bell. Its reed is larger than that of the oboe, and closer to the reed of the bassoon. Being similar to the oboe, it is a typical shawm piped instrument.
Source:
http://community.vsl.co.at/forums/t/23019.aspx http://www.williamzeitler.com/media/instruments/Hecklephone.htm
Wilhelm Heckel invented the heckelphone in 1904.
http://www.contrabass.com/pages/heckel.html
http://www.youtube.com/watch?v=hmt7cPHsDOE