Thus, for instance, an object the size of an orange held just in front of the mouth does not perceptibly interfere with the propagation of the waves produced by the speaking or singing voice, because these are from two to six feet in length: but if arrangements are made by means of a galton whistle to produce air waves half an inch in length, then an obstacle the size of an orange causes a very distinct acoustic shadow.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming
Mr. galton was Secretary of the British Association from '63-68, President of the Geographical Section in '62 and '72, and of the Anthropological Section in '77 and '85. He is President of the Anthropological Institute.
"A Biographical Dictionary of Freethinkers of All Ages and Nations"
Joseph Mazzini Wheeler
Sir John Lubbock gives an anecdote of Mr. galton, who compared the arithmetical knowledge of certain savages of South Africa and a dog.
"The Human Side of Animals"
Royal Dixon
