a transmitter. The receipt of the German signal by the receiver was duly passed to the transmitter, the signal to be repeated. The action did not guarantee automatic success. If the German bomber flew closer to its own beam than the meacon then the former signal would come through the stronger on the direction finder. The reverse would apply only if the meacon were closer. In general, German bombers were likely to get through to their targets without too much difficulty. It was to be some months before an effective night-fighter force would be ready, and anti-aircraft defences only became adequate after the Blitz was over, so ruses were created to lure German bombers away from their targets. Throughout 1940, dummy airfields were prepared, good enough to stand up to skilled observation. An unknown number of bombs fell on these diversionary ("Starfish") targets. For industrial areas, fires and lighting were simulated. It was decided to recreate normal residential street lighting, and in non-essential areas, lighting to recreate heavy industrial targets. In those sites, carbon arc lamps were used to simulate flashes at tram overhead wires. Red lamps were used to simulate blast furnaces and locomotive fireboxes. Reflections made by factory skylights were created by placing lights under angled wooden panels. The use of diversionary techniques such as fires had to be made carefully. The fake fires could only begin when the bombing started over an adjacent target and its effects were brought under control. Too early and the chances of success receded; too late and the real conflagration at the target would exceed the diversionary fires. Another innovation was the boiler fire. These units were fed from two adjacent tanks containing oil and water. The oil-fed fires were then injected with water from time to time; the flashes produced were similar to those of the German C-250 and C-500 . The hope was that, if it could deceive German bombardiers, it would draw more bombers away from the real target. First phase Loge and Seeschlange The first deliberate air raids on London were mainly aimed at the Port of London, causing severe damage. Late in the afternoon of 7 September 1940, the Germans began Operation London (Unternehmen Loge, Loge being the codename for London) and Operation Sea Snake (Unternehmen Seeschlange), the air offensives against London and other industrial cities. Loge continued for 57 nights. A total of 348 bombers and