[127] Marginal note by Viana.--"Don Miguel Gomes, who plays the engineer in this town, calls for four thousand men in his new plan of fortification. He regards the entire wall and its bastions as useless, and, just as if there were no defenses, he plans for a fortification [that would be] exceedingly costly, and of greater circuit or extent than the present one. One does not need to be very skilful to adapt to the site of Manila one of the many plans of fortification that are contained in Belidor and other noted authors. The skill of an engineer consists in being able to avail himself as far as possible of a wall, correcting its irregular shape, and putting the place in a condition of defense, with an obvious saving of expense, yet not failing to observe the rules of fortification. One of these rules is, to consider the number of men who can be maintained for its garrison, and to proportion the bastions to the number of soldiers who are there to defend them; but the said Don Miguel does not order his scheme by this rule. On the contrary, he occupies much ground, and consequently increases the number of bastions; these would remain undefended, for lack of troops, a consideration which ought to induce him to diminish the extent of the fort rather than extend it. "On the other hand, it appears that all the bastions and the curtain on the land side could be maintained as they are, without more construction than that of the esplanades, ditch, covert-ways, glacis, ravelins, etc.; for besides the wall, which is a good one, and the bastions, which are apparently well flanked, it is easy to inundate the entire locality, or reduce it to a mangrove thicket, so that it will be impenetrable to the strongest enemy--who will not be able to set up a battery, or to endure the fire from the fort while they are clearing the field from obstructions. "The curtain along the shore of the great Pasig River is a weak one, but there is sufficient soil for strengthening it; and by inundating the ground on the opposite shore of the said river the fortress will be impregnable on that side. This inundation can be made in various ways, but the safest one, in my opinion (although most expensive, on account of the greater strength which must be given to the pillars) would be to set flood-gates in all the arches of the great bridge, and in the estuaries or rivers of Binondoc and Santa Cruz, in order that the water might overflow (as it would without difficulty) the entire locality; nor would the said inundation prevent the ingress of provisions, which always come by water and not by land. The artillery of the redoubt [fortin; it defended the bridge] and the fortress would defend the said flood-gates, even though the inundation might permit the enemy to approach in order to destroy them.