The other problem Bissell wished to correct was the oscillation and chatter of the leading truck. This was accomplished by a simple centering device in the form of a pair of V-shaped double incline planes (D on fig. 3) situated at the center of the truck frame (A). The lower planes of the pair were fastened to the truck frame and the upper, cast in the form of a bridge, were attached to the locomotive frame (C) by a center plate. But while the portion of the locomotive's weight assigned to the leading wheels was borne at the center of the truck, as in the conventional design, the center plate was no longer the point of rotation. On a straight track the V's would be at their bottom position and thus prevent the truck from vibrating.[4] When the locomotive entered a curve the planes allowed its forward weight to bear continuously on all four wheels, and at the same time controlled any exaggerated swing caused by centrifugal force. The centering device is thus explained in the patent specification (figure numbers are omitted): I therefore obviate this difficulty [the oscillation of the truck] by providing two inclined planes ... formed double as shown and of an angle proportioned to the weight of the forward part of the locomotive and the velocity of the same.... The position of the inclines is such that the blocks [V's] rest in the lowest part of the double inclines when the engine is on a straight track, and on coming onto a curve the inertia of the engine ... is expended in going up the inclines, as the truck moves laterally toward the inner part of the curve; and on coming onto a straight line the blocks, descend to the bottom of the inclines and the engine is prevented from acquiring a sidewise or oscillating motion. [Illustration: FIGURE 5.--Detail drawing of the radius-bar truck, patented by William S. Hudson in 1864, as applied to the New Jersey Railroad and Transportation Company No. 44. From Gustavus Weissenborn, _American Locomotive Engineering and Railway Mechanism_, New York, 1871, pl. 8.] Bissell applied for a U.S. patent on April 23, 1857. His petition was initially denied. A weary debate of several months duration followed between the patent examiner and Bissell's attorneys. During this time Bissell was busy promoting the application of his truck even though he had no patent for protection. In May of 1857 he showed a working model of his improvement to Gilbert M. Milligan, secretary of the Central Railroad Company of New Jersey.[5] Samuel L. Moore, master mechanic of that railroad, also inspected the model. Both were so impressed that it was decided to fit the device to the locomotive _Lebanon_, which at the time was undergoing repairs at the road's Elizabeth Port, New Jersey, shops.[6] Although the engine was less than 18 months old, her tires were badly worn and she oscillated at high speed.