We know that when we speak, the sound waves that we set in motion are carried in every direction. Now when we speak into a tube, the sound waves cannot travel in all directions, but must follow the tube, and so we can hear through a tube at a greater distance than we can when speaking in the usual way.
The use of a megaphone or speaking trumpet for conveying the sound of the voice to a distance is based on the same principle.
Why do We Always Shake Hands with Our Right Hand?
The custom of shaking hands with the right hand has come down to us from the time when everyone carried a sword or knife. In those days when one met a stranger it was customary, as an indication of friendly intention, to hold out the right hand to show that it did not hold a sword or knife ready for attack.
The Story in a Billiard Table[24]
The origin of billiards is lost in antiquity. Who invented the game and the early processes of its evolution remain mysteries.
The first known reference to the game with any traditional or historical accuracy occurs in Abbe McGeoghegan’s “History of Ireland.” Cathire More, a sub-king who ruled over Leinster, died A. D. 148. The Abbe, quoting from King Cathire’s will, says, “To Drimoth I bequeath fifty billiard balls of brass with the cues of the same material.”
As early as the fifteenth century we have much evidence of the universality of the game all over southern Europe. It was certainly known in France in the time of Louis IX, who died nine years before Columbus discovered America.