“ The entry in my journal reads thus: — "Would a magnetized wheel rolling on a soft iron bar not slip, yet roll with ease; the driving wheels of a locomotive, for instance, being so covered with coils of wire that a portion or the whole of the circumference of it will be magnetized?" I send you this to show that this invention was thought of some time prior to the claims of the present inventor, and for the forcible warning it gives to every inventor to secure, by Letters Patent, every good improvement as soon as it is made. ”