ected by small pipes. The first
successful user of water-tube boilers, however, was James Rumsey, an
American inventor, celebrated for his early experiments in steam
navigation, and it is he who may be truly classed as the originator of
the water-tube boiler. In 1788 he patented, in England, several forms of
boilers, some of which were of the water-tube type. One had a fire box
with flat top and sides, with horizontal tubes across the fire box
connecting the water spaces. Another had a cylindrical fire box
surrounded by an annular water space and a coiled tube was placed within
the box connecting at its two ends with the water space. This was the
first of the "coil boilers". Another form in the same patent was the
vertical tubular boiler, practically as made at the present time.

[Illustration: Blakey, 1766]

The first boiler made of a combination of small tubes, connected at one
end to a reservoir, was the invention of another American, John Stevens,
in 1804. This boiler was actually employed to generate steam for running
a steamboat on the Hudson River, but like all the "porcupine" boilers,
of which type it was the first, it did not have the elements of a
continued success.

[Illustration: John Stevens, 1804]

Another form of water tube was patented in 1805 by John Cox Stevens, a
son of John Stevens. This boiler consisted of twenty vertical tubes, 1-1/4
inches internal diameter and 40-1/2 inches long, arranged in a circle, the
outside diameter of which was approximately 12 inches, connecting a
water chamber at the bottom with a steam chamber at the top. The steam
and water chambers were annular spaces of small cross section and
contained approximately 33 cubic inches. The illustration shows the cap
of the steam chamber secured by bolts. The steam outlet pipe "A" is a
pipe of one inch diameter, the water entering through a similar aperture
at the bottom. One of these boilers was for a long time at the Stevens
Institute of Technology at Hoboken, and is now in the Smithsonian
Institute at Washington.

[Illustration: John Cox Stevens, 1805]

About the same time, Jacob Woolf built a boiler of large horizontal
tubes, extending across the furnace and connected at the ends to a
longitudinal drum above. The first purely sectional water-tube boiler
was built by Julius Griffith, in 1821. In this boiler, a number of
horizontal water tubes were connected to vertical side pipes, the side
pipes were connected to horizontal ga