The readers of the ROUND TABLE will remember that last fall we published a photograph of the perfect model of a trolley-car which not only ran by electricity, just as an ordinary car does, but had all the details, even to advertisements, that the trolley has. This trolley-car was an extraordinary piece of work; but whereas the Warneford engine is not more than eight inches long, the trolley was between two and three feet long. The care taken in constructing the English train, engine, and road must have been infinitely greater and the difficulties considerably increased on account of its smaller size; but such work is not impossible for any one with a mechanical turn of mind. This whole railway, in fact, is a most interesting and suggestive piece of work, and illustrates what mechanical ability and ingenuity can do, and how much amusement and profit even so busy a man as an English clergyman may find in working on such a thing as a hobby. SOME DONT'S FOR SWIMMERS. BY WILLIAM HEMMINGWAY. It is just as dangerous to play with water as it is to play with fire. Probably no sport is more dangerous than swimming, just as none other is quite so delightful. If you use proper caution no exercise is safer than swimming. But what is proper caution? It is almost impossible to learn how to swim by reading any amount of printed instructions, but it is easy to learn how to take care of one's self in the water. One of the best swimming teachers I ever knew summed it all up in these words: Don't be rash. Don't be frightened. It seems to me that no advice can be better than that. I think that one more rule is safe to follow, Don't "show off." Let us look at what happens to the rash swimmer and diver. Probably every one of you has known or heard of some poor over-confident fellow who has lost his life by diving overboard without knowing the depth into which he was plunging. Nothing can be more dangerous. There is a fine swimming-beach at the upper part of the Harlem River, near Farmers' Bridge, on the Manhattan Island shore. There are bath-houses in plenty, and a long stretch of firm sandy shore. One of the best oarsmen of his year went swimming there a few years ago. He had just come to the end of five months' hard training and racing. During that long period swimming had been forbidden to men in the crew, because it was feared that they might tire themselves out at it, and use up strength that should be applied to rowing. But now the restraints of training were off, and J---- was having a delightful frolic with his friends. He was a strong swimmer and a graceful diver. Running down the beach he splashed out until he was knee-deep in the river, and then gathered himself for a dive. He plunged head first on a sand-bar. His neck was dislocated. He did not live five minutes.