escape, Harold. Had you descended that well, filled as it is with carbonic acid gas, you would have become suddenly sick and faint, and would probably have fallen senseless before you could have called for help. Make it a rule never to descend such a place without first trying the purity of its air, as you did just now.”

"But can we not get that bad air out," asked Harold.

"Yes, by various means, and some of them very easy," replied his uncle. "One is by exploding gunpowder as far down as possible; another is by lowering down and drawing up many times a thickly leaved bush, so as to pump out the foul air, or at least to mix it largely with the pure. But your knife can be obtained without all that trouble. Robert, can you not put him upon a plan?"

"I have already mentioned it, and we have come to ask if you will not let us have your magnet," replied Robert. "But," continued he smilingly, "I do not think that we shall have any need this time for the looking-glass.'

Harold looked from one to the other for an explanation, and his uncle said:

"Last year Robert dropped his knife down a well, as you did, and proposed to recover it by means of a strong magnet tied to a string. But

the well was deep and very dark, and after fishing a long time in vain, he came to me for help. I made him bring a large looking-glass from the house, and by means of it reflected such a body of sun-light down the well that we could plainly see his knife at the bottom, stowed away in a corner. The magnet was strong enough to bring it safely to the top. You also may try the experiment."

With thanks, Harold took the offered magnet, tied it to a string, and soon recovered his knife.

Chapter Fifth.

RILEY-A THUNDERSTORM-ASCERTAINING THE DISTANCE OF OBJECTS BY SOUND-SECURITY AGAINST

LIGHTNING-MEANS

OF RECOVERING LIFE FROM

APPARENT DEATH BY LIGHTNING.

A FEW days after this incident another visitor was seen coming from Fort Brooke. This person was not a horseman, but some one in a boat, who seemed even from a distance to possess singular dexterity in the use of the paddle. His boat glided over the smooth surface of the bay as if propelled less by his exertions than by his will. Dr. Gordon viewed him through the spy glass, and soon decided him to be an Indian, who was probably bringing something to sell.

It so turned out. He was a half-breed, by the name of Riley, who frequently visited the fort with venison and turkies to sell, and who on the present occasion brought with him in addition a fine green turtle. Major Burke, conceiving that his friends at Bellevue would prize these delicacies more than they at the fort, to whom they were

no longer rarities, had directed the Indian to bring them, with his compliments, to Dr. Gordon.

Riley was a fine looking fellow, of about thirty years of age-tall, keen-eyed, straight as an arrow, and with a pleasing open countenance. He brought a note from the fort, recommending him for honesty and faithfulness.

Dr. Gordon was so much pleased with his general appearance, that he engaged him to return the following week with another supply of game, and prepared to remain several days, in case he should be needed in raising the timbers of the new house.

It

Toward the close of the week, the weather gave indications of a change. A heavy looking cloud rose slowly from the west, and came towards them, muttering and growling in great anger. was a tropical thunder-storm. The distant growls were soon converted into peals. The flashes increased rapidly in number and intensity, and became terrific. Mary and Frank nestled close to their father; and even stout-hearted Harold looked grave, as though he did not feel quite so comfortable as usual.

"That flash was uncommonly keen," Robert remarked, with an unsteady voice. "Do you not think, father, it was very near?"

Instead of replying, his father appeared to be busy counting; and when the crash of thunder

was heard, jarring their ears, and making the earth quiver, he replied,

"Not very. Certainly not within a mile."

"But, uncle, can you calculate the distance of the lightring?" Harold asked.

“Unquestionably, or I should not have spoken with so much confidence. Robert imagined, as most people do, that a flash is near in proportion to its brightness; but that is no criterion. You must calculate its distance by the time which elapses between the flash and the report. Sound travels at the rate of about a mile in five seconds. Should any of you like to calculate the distance of the next flash, put your finger on your pulse, and count the number of beats before you hear the thunder."

An opportunity soon occurred. A vivid flash was followed after a few seconds by a roll, and then by a peal of thunder. All were busy counting their pulses. Mary ceased when she heard the first roll, exclaiming "Five!" The others held on until they heard the loud report, and said "Seven." Dr. Gordon reported only six beats

of his own pulse, remarking,

tant.

"That flash discharged itself just one mile disOur pulses are quicker than seconds; and yours quicker than mine. Sound will travel a mile during six beats of a person of my age, and during seven of persons of yours."

UNIVERSITY OF ILLINOIS
LIBRARY