"But if one of the balls be heavier than the other, then the centre of gravity will, in proportion, approach the larger ball." -Comstock 1850

Center of Gravity

"But if one of the balls be heavier than the other, then the centre of gravity will, in proportion,…

"The most common way of determining the density of such a body [that is heavier than water] if it is unsoluble in water, is to find its weight in air (w); find its weight when immersed in water (w'); divide the weight in air by the loss of weight in water." -Avery 1895

Scale Designed to Weigh Objects While Underwater

"The most common way of determining the density of such a body [that is heavier than water] if it is…