Your Dream Watch

The simplest of all the methods of regulating the velocity of the train, and one which certainly existed before De Vick’s time, is the fan fly, or a pair of arms with vanes which are resisted by the air. I think it by no means improbable, though it is never likely to be ascertained now, read more »

At the head of these of course stand the oldest of them all, sun-dials. But it would be a waste of time to say much about them, except in the forms in which they may be made subservient to the more useful and accurate machines by which they have been superseded. The principal feature of read more »

—It must be remembered that these are only the theoretical lengths of simple pendulums with all the weight concentrated in the centre of the bob, and that this theoretical length by no means coincides with the actual length down to the centre of gravity of the pendulum, but is always longer. This length may properly read more »