109. A locomotive with a truck is travelling over a straight level line at the rate of 60 miles an hour. A man standing at the extreme rear of the truck casts a small stone into the air in a perpendicular direction. The stone travels upward at an average rate of 30 feet per second for 3 seconds; the height of the man’s hand from ground when the stone leaves is 15 feet. At what distance behind the train will the stone strike the ground in its descent? A Tombstone in an English Cemetery. Many quaint and puzzling epitaphs are often to be seen engraved on several of the tombstones in some of the old cemeteries at Home. The adjoining illustration represents a tombstone in the old burial-ground of London--Kensal Green. It might “liven” up the reader to discover the scheme of kindred as given in the inscription. [Illustration: SACRED TO THE MEMORY OF TWO GRANDMOTHERS WITH THEIR TWO GRANDDAUGHTERS; TWO HUSBANDS WITH THEIR TWO WIVES; TWO FATHERS WITH THEIR TWO DAUGHTERS; TWO MOTHERS WITH THEIR TWO SONS; TWO MAIDENS WITH THEIR TWO MOTHERS; TWO SISTERS WITH THEIR TWO BROTHERS YET, BUT SIX CORPSES IN ALL LIE BURIED HERE-- ALL BORN LEGITIMATE FROM ERROR CLEAR.] EASILY ANSWERED. “Johnny,” said his teacher, “if your father can do a piece of work in seven days, and your uncle George can do it in nine days, how long would it take both of them to do it?” “They’d never get it done,” said Johnny; “they’d sit down and tell snake-yarns.” 110. A well is to be sunk by 12 men, in groups of 4 each, in 12 days. The groups work in the ratio of 6, 7, and 8; when half the task is done rain sets in and prevents them working for 2 days, in which time one man of the first, 2 of the second, and 3 of the third group go away, leaving the remainder to finish the job. What extra time did they work? “TAKE CARE OF THE PENCE, &c.” One of the most startling calculations is the following:-- A penny at 5 per cent. compound interest from A.D. 1 to 1890 would amount to £10,000,000,000,000,000,000,000,000,000,000,000,000, _i.e._, Ten Sextillions of pounds, or more money than could be contained in One Thousand Millions of Globes each equal to the Earth in magnitude, and all of solid gold.