Like many men before him, Mueller sought to increase the caliber of cannon without increasing weight. He managed it in two ways: he modified exterior design to save on metal, and he lessened the powder charge to permit shortening and lightening the gun. Mueller's guns had no heavy reinforces; the metal was distributed along the bore in a taper from powder chamber to muzzle swell. But realizing man's reluctance to accept new things, he carefully specified the location and size for each molding on his gun, protesting all the while the futility of such ornaments. Not until the last half of the next century were the experts well enough versed in metallurgy and interior ballistics to slough off all the useless metal. So, using powder charges about one-third the weight of the projectile, Mueller designed 14-caliber light field pieces and 15-caliber ship guns. His garrison and battering cannon, where weight was no great disadvantage, were 18 calibers long. The figures in the table following represent the principal dimensions for the four types of cannon--all cast-iron except for the bronze siege guns. The first line in the table shows the length of the cannon. To proportion the rest of the piece, Mueller divided the shot diameter into 24 parts and used it as a yardstick. The caliber of the gun, for instance, was 25 parts, or 25/24th of the shot diameter. The few other dimensions--thickness of the breech, length of the gun before the barrel began its taper, fortification at vent and chase--were expressed the same way. -----------------------------------+-------+--------+-------+--------- | Field | Ship | Siege | Garrison -----------------------------------+-------+--------+-------+--------- Length in calibers | 14 | 15 | 18 | 18 (Other proportions in 24ths of the shot diameter) | Caliber | 25 | 25 | 25 | 25 Thickness of breech | 14 | 24 | 16 | 24 Length from breech to taper | 39 | 49 | 40 | 49 Thickness at vent | 16 | 25 | 18 | 25 Thickness at muzzle | 8 | 12-1/2 | 9 | 12-1/2 -----------------------------------+-------+--------+-------+--------- The heaviest of Mueller's garrison guns averaged some 172 pounds of iron for every pound of the shot, while a ship gun weighed only 146, less than half the iron that went into the sixteenth century cannon. And for a seafaring nation such as England, these were important things. Perhaps the opposite table will give a fair idea of the changes in English ordnance during the eighteenth century. It is based upon John Mueller's lists of 1756; the "old" ordnance includes cannon still in use during Mueller's time, while the "new" ordnance is Mueller's own.