72.—­THE HYDROPLANE QUESTION.

The inhabitants of Slocomb-on-Sea were greatly excited over the visit of a certain flying man.  All the town turned out to see the flight of the wonderful hydroplane, and, of course, Dobson and his family were there.  Master Tommy was in good form, and informed his father that Englishmen made better airmen than Scotsmen and Irishmen because they are not so heavy.  “How do you make that out?” asked Mr. Dobson.  “Well, you see,” Tommy replied, “it is true that in Ireland there are men of Cork and in Scotland men of Ayr, which is better still, but in England there are lightermen.”  Unfortunately it had to be explained to Mrs. Dobson, and this took the edge off the thing.  The hydroplane flight was from Slocomb to the neighbouring watering-place Poodleville—­five miles distant.  But there was a strong wind, which so helped the airman that he made the outward journey in the short time of ten minutes, though it took him an hour to get back to the starting point at Slocomb, with the wind dead against him.  Now, how long would the ten miles have taken him if there had been a perfect calm?  Of course, the hydroplane’s engine worked uniformly throughout.

73.—­DONKEY RIDING.

During a visit to the seaside Tommy and Evangeline insisted on having a donkey race over the mile course on the sands.  Mr. Dobson and some of his friends whom he had met on the beach acted as judges, but, as the donkeys were familiar acquaintances and declined to part company the whole way, a dead heat was unavoidable.  However, the judges, being stationed at different points on the course, which was marked off in quarter-miles, noted the following results:—­The first three-quarters were run in six and three-quarter minutes, the first half-mile took the same time as the second half, and the third quarter was run in exactly the same time as the last quarter.  From these results Mr. Dobson amused himself in discovering just how long it took those two donkeys to run the whole mile.  Can you give the answer?

74.—­THE BASKET OF POTATOES.

A man had a basket containing fifty potatoes.  He proposed to his son, as a little recreation, that he should place these potatoes on the ground in a straight line.  The distance between the first and second potatoes was to be one yard, between the second and third three yards, between the third and fourth five yards, between the fourth and fifth seven yards, and so on—­an increase of two yards for every successive potato laid down.  Then the boy was to pick them up and put them in the basket one at a time, the basket being placed beside the first potato.  How far would the boy have to travel to accomplish the feat of picking them all up?  We will not consider the journey involved in placing the potatoes, so that he starts from the basket with them all laid out.

75.—­THE PASSENGER’S FARE.