“With infinite pleasure, ma’am,” said the captain, drowning in the deepest notes of his voice the feeble treble in which Noel Vanstone paid his compliments to Magdalen.  “We will start, if you please, with a first principle.  All bodies whatever that float on the surface of the water displace as much fluid as is equal in weight to the weight of the bodies.  Good.  We have got our first principle.  What do we deduce from it?  Manifestly this:  That, in order to keep a vessel above water, it is necessary to take care that the vessel and its cargo shall be of less weight than the weight of a quantity of water—­pray follow me here!—­of a quantity of water equal in bulk to that part of the vessel which it will be safe to immerse in the water.  Now, ma’am, salt-water is specifically thirty times heavier than fresh or river water, and a vessel in the German Ocean will not sink so deep as a vessel in the Thames.  Consequently, when we load our ship with a view to the London market, we have (Hydrostatically speaking) three alternatives.  Either we load with one-thirtieth part less than we can carry at sea; or we take one-thirtieth part out at the mouth of the river; or we do neither the one nor the other, and, as I have already had the honor of remarking—­down we go!  Such,” said the captain, shifting the camp-stool back again from his right hand to his left, in token that Joyce was done with for the time being; “such, my dear madam, is the Theory of Floating Vessels.  Permit me to add, in conclusion, you are heartily welcome to it.”

“Thank you, sir,” said Mrs. Lecount.  “You have unintentionally saddened me; but the information I have received is not the less precious on that account.  It is long, long ago, Mr. Bygrave, since I have heard myself addressed in the language of science.  My dear husband made me his companion—­my dear husband improved my mind as you have been trying to improve it.  Nobody has taken pains with my intellect since.  Many thanks, sir.  Your kind consideration for me is not thrown away.”

She sighed with a plaintive humility, and privately opened her ears to the conversation on the other side of her.

A minute earlier she would have heard her master expressing himself in the most flattering terms on the subject of Miss Bygrave’s appearance in her sea-side costume.  But Magdalen had seen Captain Wragge’s signal with the camp-stool, and had at once diverted Noel Vanstone to the topic of himself and his possessions by a neatly-timed question about his house at Aldborough.

“I don’t wish to alarm you, Miss Bygrave,” were the first words of Noel Vanstone’s which caught Mrs. Lecount’s attention, “but there is only one safe house in Aldborough, and that house is mine.  The sea may destroy all the other houses—­it can’t destroy Mine.  My father took care of that; my father was a remarkable man.  He had My house built on piles.  I have reason to believe they are the strongest piles in England.  Nothing can possibly knock them down—­I don’t care what the sea does—­nothing can possibly knock them down.”