 One week later, Bell built and successfully tested Gray's liquid transmitter which transmitted "Mr. Watson, come here, I want to see you" on March 10, 1876.Some writers continue to accuse Bell of stealing the telephone from Gray, Evenson claims that Bell tested Gray's water transmitter design only after Bell's patent was granted and only as a proof of concept scientific experiment to prove to his own satisfaction that intelligible "articulate speech" (Bell's words) could be electrically transmitted.Some claim that evidence exists in the Library of Congress and the U.S. Patent Office that Bell had used liquid transmitters from the time of his first electrical experiments in England in 1867 (in which he improved on the tuning fork sounder invented by Helmholtz that send musical tones over a wire using a liquid transmitter).