Image 1 of Clipping, February 7, 1918
February 7, 1918 THE COMPANION FOR ALL THE FAMILY OBSERVATION: TWIN BROTHER TO INVENTION The only copy we have Observation & Experiment no. 9 By Alexander Graham Bell DID you ever put ...
Bell, Alexander Graham
Image 2 of Clipping, February 7, 1918
of the bottom. A flat bottom should give a single sharp return, whereas an undulating bottom should give a multiple echo, such as you hear when a pistol is fired among hills. ...