these boys; I’ll show you how.’’ And he proceeded:  ``Fat cam to Phawraoh at his hinder end?’’ i.e., in his latter days.  The boys with one voice answered, ``He was drooned’’; and a smart little fellow added, ``Ony lassie could hae told you that.’’ The master then explained that in the Aberdeen dialect ``to dee’’ means to die a natural death, or to die in bed:  hence the perplexity of the boys, who knew that Pharaoh’s end was very different.’ ‘’

The author is able to add to this chapter a thoroughly original series of answers to certain questions relating to acoustics, light and heat, which Professor Oliver p 174Lodge, F.R.S., has been so kind as to communicate for this work, and which cannot fail to be appreciated by his readers.  It must be understood that all these answers are genuine, although they are not given verbatim et literatim, and in some instances one answer is made to contain several blunders.  Professor Lodge expresses the opinion that the questions might in some instances have been worded better, so as to exclude several of the misapprehensions, and therefore that the answers may be of some service to future setters of questions.  He adds that of late the South Kensington papers have become more drearily correct and monotonous, because the style of instruction now available affords less play to exuberant fancy untrammelled by any information regarding the subject in hand.

1880.—­ACOUSTICS, LIGHT AND HEAT PAPER.

          Science and Art Department.

The following are specimens of answers given by candidates at recent examinations in Acoustics, Light and Heat, held in p 175connection with the Science and Art Department, South Kensington.  The answers have not of course all been selected from the same paper, neither have they all been chosen for the same reason.

Question I.—­State the relations existing between the pressure, temperature, and density of a given gas.  How is it proved that when a gas expands its temperature is diminished?

Answer.—­Now the answer to the first part of this question is, that the square root of the pressure increases, the square root of the density decreases, and the absolute temperature remains about the same; but as to the last part of the question about a gas expanding when its temperature is diminished, I expect I am intended to say I don’t believe a word of it, for a bladder in front of a fire expands, but its temperature is not at all diminished.

Question 2.—­If you walk on a dry path between two walls a few feet apart, you hear a musical note or ``ring’’ at each footstep.  Whence comes this? p 176

Answer.—­This is similar to phosphorescent paint.  Once any sound gets between two parallel reflectors or walls, it bounds from one to the other and never stops for a long time.  Hence it is persistent, and when you walk between the walls you hear the sounds made by those who walked there before you.  By following a muffin man down the passage within a short time you can hear most distinctly a musical note, or, as it is more properly termed in the question, a ``ring’’ at every (other) step.