A catalogue of the Portland Museum, lately the property of the Duchess Dowager of Portland, deceased: which will be sold by auction, by Mr. Skinner and Co. On Monday the 24th of April, 1786, and the thirty-seven following days, at twelve o'clock, Sundays, and the 5th of June (the day his majesty's birth-day is kept) excepted; at her late dwelling-house, in Privy-Garden, Whitehall. By order of the acting executrix. [AND] A marked catalogue containing the lots, what each respectively sold for, and the names of the purchasers of the four thousand two hundred and sixty-three lots which constituted the Portland Museum; late the property of the Duchess Dowager of Portland, deceased. Which was sold by auction by Mr. Skinner and Co. and the thirty-eight following days. Enabling every connoisseur to know among whom these valuable curiosities are distributed, and the sum which every lot produced.