commenced. Within a few hundred yards scaward of Lim Point, between it and the light-house, is a little valley-a recess in the line of cliffs-where a water battery could be constructed in a few days, and which, if suitably armed and the overhanging heights properly occupied, would do all that could be done to give immediate strength to the first line of works. This valley is a couple of hundred yards farther off from Fort Point than is Lime Point, and should have heavy guns, some of them rifled. This should be done at once. Passing the first line, which could now be readily done by Lime Point, vessels intending to force an entrance into the bay would have to do so either between Alcatraz Island and the city, between Alcatraz and Angel Island, or north of Angel Island by what is called the Raccoon Straits. Vessels going between Aleatraz and the city would be exposed to the cross fire from the guns at Alcatraz, and on the city side from those at Point San Jose, or Black Point, as it is called. To go through the middle channel they would be exposed to the guns on Alcatraz and the small battery on Angel Island. This channel is very broad, and has but few large and no rifled guns bearing on it. To go through Raccoon Straits they would have the direct fire of both the batteries on Angel Island till they should be well into the straits, when they would be exposed to only those of the north battery. This battery is a small one, placed in an excavation made in a friable rocky cliff, of which the island is mainly composed, and so high above the water (which is very deep a few feet from its base) that vessels could pass close in to shore with impunity. The south battery is also at great height above the water, and would have, from the great distance at which vessels might pass from it and the caliber and kind of guns that have been provided for it, only a plunging fire. Vessels passing these batteries have northing to stop them going up to the navy-yard at Mare Island or around the bay to the city, in front of which they could lie undisturbed. On this account I wish that the temporary water batteries at the wharf on Angel Island be included in the system of defense; that earth-work batteries like those you have made on Staten Island and adjoining Fort Hamilton might at once be commenced on Yerba Buena Island and at the base of Rincon Hill, the former to aid in defending Raccoon Channel, and the latter to make it impossible for a fleet to remain if it should get within the lower lines of defense. In this harbor where large caliber and rifle guns, one or the other, or both, are especially applicable, there are but two 15-inch guns and no rifle guns whatever, and the allowance of such guns, as fixed (according to General Ramsay's report) by the Secretary of War, is for this harbor six 15-inch guns and twelve 7-inch rifle guns. In case of difficulties with a foreign maritime power (concerning which the people here are sensitive) were could get nothing from the Eastern States except with great risk. We have no establishments for casting guns. It would be impossible to send us those of the proper caliber and kind overland, and we would have to get along with those we might have on hand or which might escape hostile fleets. For this reason this coast ought to be well supplied at once and in advance of the other coasts. I do not know how far the Engineer Department have this matter (of fixing the armament) in charge, but to the extent it may have I wish some of the same enlightened judgment in this matter which gave us much a number of heavy guns for our Eastern works may do the same for the harbors of the Pacific Coast, where they are more needed than on the Atlantic. In the matter of the land batteries on Yerba Buena and at the foot of Rincon Hill in front of the Marine Hospital, and in respect to the land defenses for which recent