22 x 14,2 (diameter)
Marble and brass

INDEX 1788 : L.III.29

Haemisphaeria duo ex Marmore perpolito diametro poll. 5. quorum unicuiq. ferruminatus ê uncus ex orichalco.

Two very polished marble hemispheres with a diameter of five inches, to each one of which is soldered a brass hook.

These marble hemispheres were designed for the study of adhesion. Each of them has a highly polished flat face, both of which had to be spread with a viscous liquid or substance. The two faces were then put together. Following this, the combined hemispheres were suspended from a tripod by means of one of the hooks. Weighted bodies were suspended from the other hook in sufficient quantities to cause the separation of the hemispheres.

From Colégio dos Nobres, catalogue n.º 29.