Philosophical Transactions, Volume 37… (1731)
“ Then all Things being prepared, the Tube held hear the Boy's Feet, the Cork Ball attracted and repelled the Leaf-Brass with Force to the Hight of at least two Inches. Note, That when I speak of holding the Tube near the Boy's Feet, I mean over against the Soles of his Feet; and when near his Head, is to be understood the Crown of his Head; for when the Tube is held above, or over his Legs, the Attraction is not so strongly communicated to the other Parts of his Body. ”
