<P> Bell exhibited a working telephone at the Centennial Exhibition in Philadelphia in June 1876, where it attracted the attention of Brazilian emperor Pedro II plus the physicist and engineer Sir William Thomson (who would later be ennobled as the 1st Baron Kelvin). In August 1876 at a meeting of the British Association for the Advancement of Science, Thomson revealed the telephone to the European public . In describing his visit to the Philadelphia Exhibition, Thomson said, "I heard (through the telephone) passages taken at random from the New York newspapers:' S.S. Cox Has Arrived' (I failed to make out the S.S. Cox);' The City of New York',' Senator Morton',' The Senate Has Resolved To Print A Thousand Extra Copies',' The Americans In London Have Resolved To Celebrate The Coming Fourth Of July!' All this my own ears heard spoken to me with unmistakable distinctness by the then circular disc armature of just such another little electro - magnet as this I hold in my hand ." </P> <P> Only a few months after receiving U.S. Patent No. 174465 in the beginning of March 1876, Bell conducted three important tests of his new invention and telephone technology after returning to his parents' home at Melville House (now the Bell Homestead National Historic Site) for the summer . </P> <P> In the first test call on August 3, 1876, Alexander Graham's uncle, Professor David Charles Bell, spoke to him from the Brantford telegraph office, reciting lines from Shakespeare's Hamlet ("To be or not to be ..."). The young inventor, positioned at the A. Wallis Ellis store in the neighboring community of Mount Pleasant, received and may possibly have transferred his uncle's voice onto a phonautogram, a drawing made on a pen - like recording device that could produce the shapes of sound waves as waveforms onto smoked glass or other media by tracing their vibrations . </P> <P> The next day on August 4 another call was made between Brantford's telegraph office and Melville House, where a large dinner party exchanged "...speech, recitations, songs and instrumental music". To bring telephone signals to Melville House, Alexander Graham audaciously "bought up" and "cleaned up" the complete supply of stovepipe wire in Brantford . With the help of two of his parents' neighbours, he tacked the stovepipe wire some 400 metres (a quarter mile) along the top of fence posts from his parents' home to a junction point on the telegraph line to the neighbouring community of Mount Pleasant, which joined it to the Dominion Telegraph office in Brantford, Ontario . </P>

Who invented the telephone and when was it invented