A key to Alexander Graham Bell's experiments was one of these, procured by a doctor friend, Clarence Blake
IN THESE GROUPS ... His 
education was largely received through numerous experiments in sound ... At 
age 12, while playing with a friend in a grain mill, he noticed the... [DOC] [TLE] Alexander Graham Bell - The Canadian Encyclopedia [PAR] Alexander Graham Bell, teacher of the deaf, inventor, scientist (born 3 March ... 
Much of Bell's work can be described as a series of observations leading one to 
another.