In later years, powder charges lessened for all guns. English velocity tables of the 1750's show that a 9-pounder charged with 2-1/4 pounds of powder might produce its ball at a rate of 1,052 feet per second. By almost tripling the charge, the velocity would increase about half. But the increase did not mean the shot hit the target 50 percent harder, for the higher the velocity, the greater was the air resistance; or as Mueller phrased it: "a great quantity of Powder does not always produce a greater effect." Thus, from two-thirds the ball's weight, standard charges dropped to one-third or even a quarter; and by the 1800's they became even smaller. The United States manual of 1861 specified 6 to 8 pounds for a 24-pounder siege gun, depending on the range; a Columbiad firing 172-pound shot used only 20 pounds of powder. At Fort Sumter, Gillmore's rifles firing 80-pound shells used 10 pounds of powder. The rotating band on the rifle shell, of course, stopped the gases that had slipped by the loose-fitting cannonball. Black powder was, and is, both dangerous and unstable. Not only is it sensitive to flame or spark, but it absorbs moisture from the air. In other words, it was no easy matter to "keep your powder dry." During the middle 1700's, Spaniards on a Florida river outpost kept powder in glass bottles; earlier soldiers, fleeing into the humid forest before Sir Francis Drake, carried powder in _peruleras_--stoppered, narrow-necked pitchers. As for magazines, a dry magazine was just about as important as a shell-proof one. Charcoal and chloride of lime, hung in containers near the ceiling, were early used as dehydrators, and in the eighteenth century standard English practice was to build the floor 2 feet off the ground and lay stone chips or "dry sea coals" under the flooring. Side walls had air holes for ventilation, but screened to prevent the enemy from letting in some small animal with fire tied to his tail. Powder casks were laid on their sides and periodically rolled to a different position; "otherwise," explains a contemporary expert, "the salt petre, being the heaviest ingredient, will descend into the lower part of the barrel, and the powder above will lose much of its goodness." [Illustration: Figure 17--SPANISH POWDER BUCKET (c. 1750).] In the dawn of artillery, loose powder was brought to the gun in a covered bucket, usually made of leather. The loader scooped up the proper amount with a ladle (fig. 44), and inserted it into the gun. He could, by using his experienced judgment, put in just enough powder to give him the range he wanted, much as our modern artillerymen sometimes use only a portion of their charge. After Gustavus Adolphus in the 1630's, however, powder bags came into wide use, although English gunners long preferred to ladle their powder. The powder bucket or "passing box" of course remained on the scene. It was usually large enough to hold a pair of cartridge bags.