insulating stool
Webster's Dictionary (GCIDE)
Insulate \In"su*late\, v. t. [imp. & p. p. Insulated; p. pr. & vb. n. Insulating.] [L. insulatus insulated, fr. insula island. See Isle, and cf. Isolate.] [1913 Webster]
1.To make an island of. [Obs.] --Pennant. [1913 Webster]
2.To place in a detached situation, or in a state having no communication with surrounding objects; to isolate; to separate. [1913 Webster]
3.(Elec. & Thermotics) To prevent the transfer of electricity or heat to or from (bodies) by the interposition of nonconductors. [1913 Webster]
Insulating stool (Elec.), a stool with legs of glass or some other nonconductor of electricity, used for insulating a person or any object placed upon it. [1913 Webster]