“Oh dear no,” replied Tom; “Louisa merely observed, that we might now be able to find out the depth of the village well, about which we have all been very curious; for the gardener has told us that it is the deepest in the kingdom, and was dug more than a hundred years ago.”
Mr. Seymour did not believe that it was the deepest in the kingdom, although he knew that its depth was considerable; and he said that, if Mr. Twaddleton had no objection, they should walk to it, and make the proposed experiment.
“Objection! my dear Mr. Seymour, when do I ever object to afford pleasure to my little playmates, provided its indulgence be harmless? Let us proceed at once, and on our return I hope you will favour me with a visit at the vicarage; I have some antiquities which I am anxious to exhibit to yourself and Mrs. Seymour.” Tom and Rosa each took the vicar’s hand, and Mr. and Mrs. Seymour followed with Louisa and Fanny. The village well was about half a mile distant; the road to it led through a delightful shady lane, at the top of which stood the vicarage-house. Mr. and Mrs. Seymour and her daughters had lingered in their way to collect botanical specimens; and when they had come up to Tom and the vicar, they found them seated on the trunk of a newly-felled oak, in deep discourse.
“What interests you, Tom?” said Mr. Seymour, who perceived, by the enquiring and animated countenance of the boy, that his attention had been excited by some occurrence.
“I have been watching the woodman,” said Tom, “and have been surprised that the sound of his hatchet was not heard until some time after he had struck the tree.”
“And has not Mr. Twaddleton explained to you the reason of it?” asked Mr. Seymour.
“He has,” replied Tom, “and he tells me that it is owing to sound travelling so much more slowly than light.”
“You are quite right; and as we are upon an expedition for the purpose of measuring depths, it may not be amiss to inform you, that this fact furnishes another method of calculating distances.”
The party seated themselves upon the oak, and Mr. Seymour proceeded--“The stroke of the axe is seen at the moment the woodman makes it, on account of the immense velocity with which light travels;[(3)] but the noise of the blow will not reach the ear until some time has elapsed, the period varying, of course, in proportion to the distance, because sound moves only at the rate of 1142 feet in a second, or about 13 miles in a minute; so that you perceive, by observing the time that elapses between the fall of the hatchet and the sound produced by it, we can ascertain the distance of the object.”
Mr. Seymour fixed his eye attentively on the woodman, and, after a short pause, declared that he was about half a quarter of a mile distant.