due to sunspots, as the flux appeared to vary with the number of visible spots. The resolution of the device, about seven degrees, made it impossible to "pick out" a spot on the sun's surface for study, making a demonstration of the claim difficult. An opportunity to directly measure this possibility presented itself on November 23, 1946, when a partial solar eclipse passed over the Ottawa area, and Covington was able to conclusively demonstrate that the microwave emissions dropped off precipitously when the Moon covered a particularly large sunspot. This also demonstrated that magnetic fields were instrumental in sunspot activity. It was entirely by accident that the original instrument operated on frequencies suitable to detection of the 10.7 cm signal, and it had never been intended for "production" use. As the importance of the sunspot measurements became obvious, plans were made to continue these observations over a longer time period. As the Radio Field Station was still actively being used for radar development, and causing heavy interference as a result, a new location was selected about five miles (8 km) away at Goth Hill. Here they measured the whole-disk flux and averaged the measurements to produce three highly accurate measurements a day. He then set about designing an instrument that could directly resolve portions of the sun's disk. The new telescope consisted of a 150 ft (46 m) long section of 3 by 1½ inch metal waveguide cut with slots in locations to create a simple interferometer with a fan-shaped area of sensitivity. The amount of flux gathered was improved by placing the waveguide in metal trough, and the direction of aim could be changed slightly by rotating the waveguide inside the trough, but in general terms it was used to take measurements as the sun passed through its "beam". The new telescope started operation in 1951, allowing them to directly measure the flux from the Sun's corona and the temperature of the regions above sunspots (about 1,500,000 °C). The Goth Hill observatory also included a number of other instruments for a variety of measurements. ARO Increasing radar and radio use in the Ottawa area presented interference problems, and Covington turned his attention to finding a more suitable "radio quiet" location for the program. This led to the creation of the Algonquin Radio Observatory (ARO) in Algonquin Park, about 150 km northwest of Ottawa but relatively easy to access on