But now a great development was at hand, and a new chapter was to commence in the story.
CHAPTER IV. THE PEARL-BUTTON MAKER'S CONTRIVANCE. THE MODERN FIRE-ENGINE.
How to force a continuous stream of water on the fire!
That was the problem which puzzled an unknown inventor about the year 1675. He probably saw that hitherto the appliances for extinguishing conflagrations failed at this point, and we may suppose that he cudgelled his brains to hit upon the right remedy.
Then one day, no one seems to know when, he thought of inventing, or adapting, the compressed air-chamber to a sort of portable pump, and, behold!—
The Modern Fire-Engine was born!
The invention was introduced, probably, after the Great Fire, because authorities describe it as first mentioned in the French Journal des Savans in 1675, and Perrault states that an engine with an air-chamber was kept at Paris for the protection of the Royal Library in 1684. If, therefore, Hero knew of the air-chamber, as some assert, it does not appear to have been much used. But probably the great disaster in London stirred invention, and the addition of the air-chamber was the result. It may not, however, have been a distinct invention, for an air-chamber had been found of great value in various hydraulic machines.
What, then, is this invention, and what is its great value to a fire-engine?
Briefly, it enables a steady and continuous stream of water to be thrown on a fire. It is the vital principle of the modern fire-engine, and renders it distinctly different from all squirts, syringes, and portable pumps preceding it. Instead of an unequal and intermittent supply, sometimes, no doubt, falling far short of the fire, we have now a persistent stream, which can be continuously directed to any point, in reach, with precision and efficiency.