Yet it is evident that this too was a necessary step which made the later triumphs possible.
If we combine the scientific and the artistic efforts of the new and the old world, we may tell the history of the moving pictures by the following dates and achievements.

In the year 1825 a Doctor Roget described in the "Philosophical Transactions" an interesting optical illusion of movement, resulting, for instance, when a wheel is moving along behind a fence of upright bars.

The discussion was carried much further when it was taken up a few years later by a master of the craft, by Faraday.

In the _Journal of the Royal Institute of Great Britain_ he writes in 1831 "on a peculiar class of optical deceptions." He describes there a large number of subtle experiments in which cogwheels of different forms and sizes were revolving with different degrees of rapidity and in different directions.

The eye saw the cogs of the moving rear wheel through the passing cogs of the front wheel.