In 1886, when Erskine was living in London, sold more of his collection. The British Museum bought from Erskine an brass astrolabe with a silver inlay. Erskine's astrolabe was from Iran, and made in the 16th or 17th centuries, during the Safavid Empire. Before Erskine owned the astrolabe, Claudius Rich was its owner. (Rich was a relative of Erskine's because Rich had married Erskine's mother's older sister, Mary Mackintosh.) Rich had got the astrolabe in Yazd. The British Museum paid Erskine £18 for it. The museum also bought other things from Erskine that year. Erskine had got from Rich a sword and sheath from the Ottoman Empire that were from the 16th or 17th centuries. The British Museum bought these in 1886. The next year, the British Museum bought more of Erskine's objects.