a direct remedy because the offending streets are naturally at the point of their offending on an equal level and it becomes necessary either to substitute for one of the offenders another line of route, the levels of which favour the introduction of a viaduct, or to arrange that the crossing shall take place in some position where space is available for the necessary rise and fall of the two roads. As an example I offer an illustration of a scheme of my own for forming an over-and-under crossing for extensive traffic in Russell Square, London. (Fig. 2.)
Another device, hitherto but little tried, if at all, is a circus on what may be called the "merry-go-round" principle—otherwise the "gyratory" crossing. The roads, whether four cross roads or junctions of traffic with more radiations than four, meet at a circus like Oxford Circus, but with these important differences—first that vehicles are compelled to circulate in the circus—not to dash straight across it, and second, that in furtherance of this system the centre of the circus instead of being roadway is filled in, either by a pavement with fountain and trees or by a garden space or again with a circular block of buildings. (Fig. 3.)
I observed that the town-planner when called in consultation would before sanctioning a widening consider whether some other device would not really meet the difficulty better. I might have put the matter in another way by saying that the first duty of a town-planner, when confronted with a problem, is not to see how the proposed remedy can best be applied and devised, but to proceed to the diagnosis of the problem itself.