Complex sentence: He then put on one of a pair of leather gauntlets, which his counsel (Mr. Reader) had handed him, and he threw down the other for William Ashford to pick up and thus accept the challenge, which Ashford did not do.
Split into simpler sentences: He then put on one of a pair of leather gauntlets, which his counsel (Mr. Reader) had handed him. Thornton threw down the other for William Ashford to pick up and thus accept the challenge, which Ashford did not do.