Weelll . . . [pedantic mode] the bulk density of granulated sugar is actually lower than that of water, so your 9 lbs of sugar should have taken up more volume than your 6 pints of water, as well as weighing more. Allow for the air between the granules & the density goes up a lot, but the total volume is still similar to that of the water, so 'far greater volume' only applies to the mix, not the water.[/pedantic mode]