a block. He would rise, shake himself together, and endeavour to pursue his journey, and be again repelled. More than likely he would try three times before he became convinced that it really was something in the air itself which stopped him. Then he would thrust with his stick and feel, more and more astounded every moment, and scarcely able to believe his own senses. During the day, otherwise engaged, he would argue himself into the view that he had made a mistake, and determine to try again, though more cautiously. But so strong is habit that if a cause for alarm arose, and he started running, he might quite probably go with tremendous force up to the solid block of transparent air, to be hurled back as the jack was.
These are no mere suppositions, for quite recently I heard of a case which nearly parallels the conduct of the jack. A messenger was despatched by rail to a shop for certain articles, and was desired to return by a certain time. The parcel was made up, the man took it, heard an engine whistle, turned to run, and in his haste dashed himself right through a plate-glass window into the street. He narrowly escaped decapitation, as the great pieces of glass fell like the knife of a guillotine. Cases of people injuring themselves by walking against plate-glass are by no means uncommon; when the mind is preoccupied it takes much the same place as the plate of glass in the water and the jack. Authorities on mythology state that some Oriental nations had not arrived at the conception of a fluid heaven—of free space; they thought the sky was solid, like a roof The fish was
