Sentence:  But then I had the flintlock by me for protection. ¶ There were giants in the days when that gun was made; for surely no modern mortal could have held that mass of metal <WSD>steady</WSD> to his shoulder. The linen-press and a chest on the top of it formed, however, a very good gun-carriage; and, thus mounted, aim could be taken out of the window,nb.... 
Meaning of the word marked with <WSD> tags:  Firm in standing or position; not tottering or shaking; fixed; firm.