During his long period in command of "Shannon", Captain Philip Broke of the Royal Navy introduced many practical refinements to his 'great guns', which were virtually unheard of elsewhere in contemporary naval gunnery. He had 'dispart sights' fitted to his 18-pounder long guns, which improved aiming as they compensated for the narrowing of the barrels from the breech to the muzzle. He had adjustable tangent sights that would give accuracy at different ranges. He had the elevating 'quoins' (wedge-shaped pieces of wood placed under the breech) of his long guns grooved to mark various degrees of elevation so that his guns could be reliably levelled to fire horizontally in any state of heeling of the ship under a press of sail. The carronades were similarly treated, but the elevating screws on these cannon were marked in paint. As the decks of contemporary ships curved upwards towards the stern and bows, he cut down the wheels on the "up-slope" side of each cannon's carriage in order that all guns were level with the horizon. He also introduced a system where bearings were incised into the deck next to each gun; fire could then be directed to any bearing independent of the ability of any particular gun crew to see the target. Fire from the whole battery could also be focused on any part of an enemy ship.