- Software name: appdown
- Software type: Microsoft Framwork
- size: 298MB
An apprentice may learn that power is not increased or diminished by being transmitted through a train of wheels which change both speed and force, and he may believe the proposition without having a "conviction" of its truth. He must first learn to regard power as a constant and indestructible elementsomething that may be weighed, measured, and transmitted, but not created or destroyed by mechanism; then the nature of the mechanism may be understood, but not before.
He had almost reached the top of the hill, and was about to change his gear, when a figure loomed up out of the darkness and made straight for the car. The Doctor hastily jammed his brake down, but too late to avert a collision. There was a violent bump; and the next moment the car began running backwards down the hill, followed by the figure, who had apparently suffered no inconvenience from the contact.
"I couldn't possibly come before," he said. "I've been busy all the evening on this business, and as it was I had to leave a little matter to chance. I fancy that you will not be sorry that I persuaded you to stay in London."
As reading books of fiction sometimes expands the mind and enables it to grasp great practical truths, so may a study of abstract principles often enable us to comprehend the simplest forms of mechanism. Even Humboldt and Agassiz, it is said,  resorted sometimes to imaginative speculations as a means of enabling them to grasp new truths.