"We came back from the garden by the river road, and crossed the bridge to Calcutta once more. Then we went to see Dalhousie Square, or Tank Square, as it was formerly called, and have a stroll around its borders. It is right in the middle of the city, and appears to be twenty or twenty-five acres in extent; there is a fence all the way around it, and the banks are nicely sodded and covered with grass. You will wonder when we say that there is a great reservoir in the centre fed entirely by springs at the bottom, and the supply is so great that it never goes dry. The fact is, the whole city of Calcutta rests on a bed of quicksand, through which the water from the Ganges finds its way with the greatest ease. The tank was originally dug to supply the inhabitants with water, and they had only to go a few feet below the level of the river to find the water coming through the sand and bubbling up perfectly pure. The sand cleansed it from all impurities, and it has always been regarded as the sweetest water in the city. "When we reached the north-west corner of Tank Square our guide indicated a spot where there was once an obelisk to the memory of the men who perished in the famous Black Hole: the Black Hole was a room in a building close by here, but both building and obelisk have disappeared. You remember the story: On the capture of Calcutta by Surajah Dowlah, in 1746, 146 Englishmen were forced into a room only eighteen feet square, with two small windows on the western side, and left there till morning. The night was hot and damp, and there was no wind blowing, and in the morning only twenty-three of all the number were alive. Several of these never recovered--thirst and foul air caused the most terrible sufferings, ending in death, and the name of Black Hole is frequently applied to a place that is badly ventilated. [Illustration: BENGALESE WATER-CARRIERS.] "The native water-carriers are a curiosity; they supply houses that are without running water, and are employed to sprinkle the streets when the dust is likely to rise. Their equipment is very simple, as it consists of the skin of a pig or goat--generally of a pig, as it will hold water better than the other. The skin is carefully sewed up, with the exception of the neck, which is left open to receive the water; you frequently see these men going around with their burdens, and the price they get for bringing water is so small that they must be very diligent to earn twenty-five cents a day.