Sentence:  The defect for the complete "<WSD>mounture</WSD>" of the Navy brass ordnance is 400 pieces; the Parliament in 1624 provided 500 iron ordnance with their carriages and other equipage for the <WSD>mounture</WSD> of 50 colliers to attend his Majesty's, fleet, which since have otherwise been disposed of, so that now none are remaining in the magazine for that service. 
Meaning of the word marked with <WSD> tags:  The act or process of mounting.