Isham arrived at York Fort on Hudson Bay at 16 in 1732, employed by the company as a "writer." He learned account-keeping and became an adept factor, as well as a highly regarded natural historian. His Observations on Hudson's Bay was one of several manuscripts that returned to England with him when he was recalled temporarily from Churchill in 1745 on account of poor health. He submitted the manuscripts to the HBC's governor and committee, who appear to have ignored them. Observations were only finally published in this volume. In 1748 Isham was again recalled to London, this time to comment on a book by Henry Ellis on a Northwest Passage search by a 1746-47 expedition that also had designs on challenging the HBC's monopoly. Ellis's narrative was unflattering to Isham. Notes and Observations on a book? was Isham's response, provided to the governor and committee. Appendixes include Isham's 1746-47 journal, a description of native groups from Andrew Graham's Observations on Hudson's Bay (1775), and biographical sketches.