In the early Mediterranean galley the cannon was mounted in a wooden trough placed fore and aft on the deck in the bow of the vessel. The trough was secured to the deck. In rear of the cannon’s breech and in contact with it was a massive bitt of timber, worked vertically, which took the force of the recoil. Later, as force of powder increased, this non-recoil system of mounting ordnance failed. The cannon had to be given a certain length of free recoil in order that, by the generation of momentum, the energy which would otherwise be transmitted to the ship in the form of a powerful blow might be safely diverted and more gradually absorbed. Hence free recoil was allowed within certain limits, the cannon being secured with ropes or chains. But, as had doubtless been found already with land ordnance, the violence of recoil depended largely upon the mass of the recoiling piece; for any given conditions of discharge the heavier the gun, the less violent was its recoil. It was a natural expedient, then, to make the recoiling mass as large as possible. And this could be effected, without the addition of useless and undesirable extra deadweight, by making the wooden trough itself partake of the recoil. The cannon was therefore lashed solidly to the trough, and both gun and trough were left free to recoil in the desired direction. The primitive mounting helped, in short, by augmenting the weight of the recoiling mass, to give a quiet recoil and some degree of control over the piece. Later, this trough or baulk of timber performed an additional function when used as a mounting for a certain form of gun. When the piece was a breech-loader--like those recovered from the wreck of the _Mary Rose_--the trough had at its rear end a massive flange projecting upwards, forming the rear working face for the wedge which secured the removable breech chamber to the gun. “The shot and wadde being first put into the chase,” wrote Norton in 1628, “then is the chamber to be firmly wedged into the tayle of the chase and carriage.” The mounting was, in fact, an integral part of the gun. In the 8-inch breech-loading equipment of the _Mary Rose_ which lies in the museum of the Royal United Service Institution in Whitehall there is evidence of two small rear wheels. Most of these early ship carriages had two wheels, but for the more powerful muzzle-loaders introduced toward the middle of the sixteenth century, four came into favour. With four wheels our timber baulk has become a primitive form of the truck carriage of the succeeding centuries.[90]