It’s not as difficult to estimate the weight of a human hand as John Pye thinks – and can be accomplished in the average kitchen (Letters, 17 August).
Take a transparent jug that is tall enough to take the outstretched hand, although a loose fist could be used with a shorter jug. Weigh the jug. Put in a measured amount of water that is sufficient to cover the hand without spilling over when the hand is put in. This is best done using kitchen scales that are accurate to one or two grams.
Immerse the hand or fist up to the wrist. With the free hand, mark the level of water in the jug. Take out the hand, being careful not to drip any water outside of the jug. Top up the jug with water as far as the mark. Weigh the jug with the extra water and subtract both the weight of the jug and the original measured amount of water. This weight of water in grams is numerically equal to the volume of the hand in cubic centimetres because 1cc of water weighs 1g.
Multiply the volume in cubic centimetres by the density of the hand – one study suggests hand density as 1.09 g/cc – and that will be a reasonable estimate of the weight of the hand, plus or minus about 10g.
Dr Ken Vines
Horrabridge, Devon
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