Chapter 2

And, knitting his
 Brows, he lapsed into an introspective state, his lips moving as one
 Who repeats mystic words. 'Yes, I think I see it now,' he said after
 Some time, brightening in a quite transitory manner.
 'Well, I do not mind telling you I have been at work upon this
 Geometry of Four Dimensions for some time. Some of my results
 Are curious. For instance, here is a portrait of a man at eight
 Years old, another at fifteen, another at seventeen, another at
 Twenty-three, and so on. All these are evidently sections, as it
 Were, Three-Dimensional representations of his Four-Dimensioned
 Being, which is a fixed and unalterable thing.
 'Scientific people,' proceeded the Time Traveller, after the pause
 Required for the proper assimilation of this, 'know very well that
 Time is only a kind of Space. Here is a popular scientific diagram,
 A weather record. This line I trace with my finger shows the
 Movement of the barometer. Yesterday it was so high, yesterday night
 It fell, then this morning it rose again, and so gently upward to
 Here. Surely the mercury did not trace this line in any of the
 Dimensions of Space generally recognized? But certainly it traced
 Such a line, and that line, therefore, we must conclude was along
 The Time-Dimension.'
 'But,' said the Medical Man, staring hard at a coal in the fire, 'if
 Time is really only a fourth dimension of Space, why is it, and why
 Has it always been, regarded as something different? And why cannot
 We move in Time as we move about in the other dimensions of Space?'
 The Time Traveller smiled. 'Are you sure we can move freely in
 Space? Right and left we can go, backward and forward freely enough,
 And men always have done so. I admit we move freely in two
 Dimensions. But how about up and down? Gravitation limits us there.'
 'Not exactly,' said the Medical Man. 'There are balloons.'
 'But before the balloons, save for spasmodic jumping and the
 Inequalities of the surface, man had no freedom of vertical
 Movement.'
 'Still they could move a little up and down,' said the Medical Man.
 'Easier, far easier down than up.'
 'And you cannot move at all in Time, you cannot get away from the
 Present moment.'
 'My dear sir, that is just where you are wrong. That is just where
 The whole world has gone wrong. We are always getting away from the
 Present moment. Our mental existences, which are immaterial and have
 No dimensions, are passing along the Time-Dimension with a uniform
 Velocity from the cradle to the grave. Just as we should travel _down_
 If we began our existence fifty miles above the earth's surface.'
 'But the great difficulty is this,' interrupted the Psychologist.
 'You _can_ move about in all directions of Space, but you cannot
 Move about in Time.'
 'That is the germ of my great discovery. But you are wrong to say
 That we cannot move about in Time. For instance, if I am recalling
 An incident very vividly I go back to the instant of its occurrence:
 I become absent-minded, as you say. I jump back for a moment. Of
 Course we have no means of staying back for any length of Time, any
 More than a savage or an animal has of staying six feet above the
 Ground. But a civilized man is better off than the savage in this
 Respect. He can go up against gravitation in a balloon, and why
 Should he not hope that ultimately he may be able to stop or
 Accelerate his drift along the Time-Dimension, or even turn about
 And travel the other way?'
 'Oh, _this_,' began Filby, 'is all--'
 'Why not?' said the Time Traveller.
 'It's against reason,' said Filby.
 'What reason?' said the Time Traveller.
 'You can show black is white by argument,' said Filby, 'but you will
 Never convince me.'
 'Possibly not,' said the Time Traveller. 'But now you begin to see
 The object of my investigations into the geometry of Four
 Dimensions. Long ago I had a vague inkling of a machine--'
 'To travel through Time!' exclaimed the Very Young Man.
 'That shall travel indifferently in any direction of Space and Time,
 As the driver determines.'