Judging from his critiques Anson had books with him, though we don’t know how many. He was especially critical of the work of Frazier:
p. 91: But to have done with Frezier, whose errors, the importance of the subject and not a fondness for caviling, has obliged me to remark, (though his treatment of Dr. Halley might, on the present occasion, authorize much severer usage) I must, in the next place, particularize wherein the chart I have here inserted differs from that of our learned countryman. [Goes on to say how he has corrected the charts of Frezier and others.]