It had been laid down by Dr. Hutton in 1775, as one of the chief results of the systematic experiments carried out by him at Woolwich in extension of the inquiries originated by Robins, that if only the windage of guns could be reduced very important advantages would accrue; among others, a saving of at least one-third of the standard charges of powder would result. General Melville determined to give the Smasher the very minimum of windage necessary to prevent accident. The shortness of the bore favoured such a reduction. The large diameter, though at first it might appear to render necessary a correspondingly large windage, was actually an advantage from this point of view. For, instead of adhering to the orthodox practice with long guns, of making the windage roughly proportional to the diameter of the bore, he gave the Smasher a windage less than that of a much smaller long gun, arguing that though a certain mechanical clearance was necessary, yet the amount of this clearance was in no way dependent on the diameter of the shot or piece. The large size of the Smasher acted therefore to its advantage. The windage space through which the powder gases could escape was very small in relation to the area of the large ball on which they did useful work. But this divergence from the standard practice would appear to necessitate the provision of special ammunition for use with the Smasher: the nicely fitting sixty-eight pound ball would require to be specially made for it? And this would surely militate against the general adoption of the Smasher in the public service? No such difficulty confronted the inventor. For, curiously enough, the principle on which the dimensions of gun-bores and shot were fixed was the reverse of the principle which obtains to-day. Instead of the diameter of the _gun_ being of the nominal dimension and the diameter of the shot being equal to that of the gun minus the windage, the diameter of the _shot_ was the datum from which the amount of the windage and the calibre of the gun were determined.