An auxiliary brigade, consisting of one regiment and one battalion of infantry and a mountain battery of artillery, was formed at Calumpit, on the Island of Luzon, to ascend the left bank of the Rio Grande, and to form a junction with Lawton some distance above. This expedition was accompanied by two gunboats belonging to the "mosquito fleet," and one launch used to tow the cascoes, or native freight barges, bearing an extra supply of rations and ammunition. This was in May, 1899. I was provost-marshal of this expedition. When we first entered a town or city, after capturing it, it was my duty to find out what buildings contained valuable property, and immediately place a guard over them, in order to prevent the place from being looted. Large warehouses containing immense quantities of rice, sugar, silks, pina cloth, and other things equally as precious, were frequent finds. They had to be guarded. We met with but little resistance on this expedition till we reached the town of San Luis, about twelve miles up the river from Calumpit. The heavy fire of our infantry and artillery, ably assisted by the little "pepper-boxes" afloat, soon put our dusky enemies to flight; and we marched straight into town, with colors flying, over trenches, barricades, and other obstructions hastily thrown in our way. Among the largest stone buildings of San Luis was the "tribunal," or public house, something after the style of our town halls, with the difference that it is always open for strangers, who cook, eat, and sleep in it. Among other useful apartments, it had a cell, probably used as a "jug" into which the native policemen ran the over-exuberant youth who was guilty of imbibing too freely of his cherished "vino," or the head of the family for the non-payment of taxes, or allowing his water buffalo to play in his neighbor's yard. Previous to the occupation of the town by the Americans, this dungeon-like cell had been occupied by Spanish prisoners, who were held by Aguinaldo's army. When I first saw the room, not more than ten minutes after our arrival, I saw one of as sickening sights as any person ever beheld. This dungeon, or cell, was about ten feet high, the same in width, and about fifteen feet in length. Through one small grated window passed all the light that ever cheered this ante-chamber of hell. The door leading into it was in a dark corner, and when one was on the inside, he scarcely noticed whether it was open or closed.