be effected as easily as to a few". However, Fessenden would almost exclusively focus on point-to-point transmissions intended to supplement the wire telephone system. Lee de Forest was even more ambitious, although Herrold would later incorrectly assert that "Certainly de Forest had no thought of a broadcast". As early as June 1907, a review of de Forest's test of his version of a Valdemar Poulsen arc transmitter noted that "the inventor believes that by using four different forms of wave as many classes of music can be sent out as desired by the different subscribers". De Forest made a series of musical demonstrations from 1907 to 1910, although he would not actually begin regular broadcasts until 1916, when vacuum-tube transmitters became available. Radio development pre-WWI On January 1, 1909, Herrold opened the Herrold College of Wireless and Engineering, located in the Garden City Bank Building at 50 West San Fernando Street in San Jose, where a huge "umbrella-style" antenna was constructed atop the building. The college's primary purpose was to train radio operators, for handling communications aboard ship or staffing shore stations. Although he would never get a degree, Herrold became known as "Doc" as a sign of his student's respect. Ray Newby, just 16 years old, acted as his primary assistant. At the time Herrold began his work, there was no regulation of radio stations in the United States, and the station was identified by self-assigned call letters, including FN and SJN. Later the Radio Act of 1912 mandated the licensing of stations, and Herrold was issued a license for an Experimental station in late 1915, with the call sign 6XF. Herrold's primary radiotelephone effort was toward developing a commercial system suitable for point-to-point service. Working with Ray Newby, he initially used high-frequency spark transmitters. In a June 23, 1910 notarized letter that was published in a catalog produced by the Electro Importing Company of New York, Herrold reported that, using one of that company's spark coils, he had successfully broadcast "wireless phone concerts to local amateur wireless men". However, the limitations of the high-frequency spark soon became apparent, and he switched to developing refined versions of the Poulsen arc, which was more stable and had better audio fidelity. In early 1912, Herrold was hired as chief engineer of the National Wireless Telephone and Telegraph Company in San Francisco. With hopes that they could develop a highly profitable point-to-point