Given the task definition and input, reply with output. In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.

Passage: In the early 1660s, a building program was initiated to expand the fleet and replace old capital ships. A new flagship was needed to replace the old Kronan from 1632. The felling of vast quantities of timber that were required for the new admiral's ship had already begun in the winter of 1664–65. Swedish historian Kurt Lundgren has estimated that 7–10 hectares (17–25 acres) of hundred-year-old oak forest was required for the hull and several tall, stout pines for the masts and bowsprit.The construction of Kronan began in October 1665, and the hull was launched on 31 July 1668. The English shipwright Francis Sheldon frequently came in conflict with the admiralty over the project. The navy administrators complained that he was unduly delaying the project and was spending too much time on his own private business ventures. The most aggravating contention was Sheldon's extensive and lucrative export of mast timber to England. Sheldon in turn complained about constant delays on the navy's part and lack of funds. When the ship was launched, the slipway turned out to be too small and the rear section of the keel broke off during the launching. The admiralty demanded an explanation, but Sheldon's reply was that the damage was easily mended and that the problem was that the timber had been left to dry too long. The conflict between the Admiralty and Sheldon dragged on for several years and caused constant delays. The sculptures were finished in 1669, but the rigging, tackling, and arming was drawn out a further three years, to 1672. The first occasion that the ship sailed was during the celebrations of Charles XI's accession as monarch in December 1672.
What was the shipwright's other business?