it was inclined to squirm and struggle against the makeshift harness , making several abortive attempts to leap off into the air , until temeraire lifted away ; then after a few yelps of excitement , it sat down on its haunches with its mouth open and tongue lolling out , thrashing its tail furiously with delight , better pleased than its unhappy master , who clung anxiously to the harness and to sipho , although they were both well hooked on with carabiners .