applied for a
patent for "Improvements in the Manufacture of Iron and Steel."[14]
This covered the fusion of steel with pig or cast iron and, though this
must be regarded as only the first practical step toward the Bessemer
process,[15] it was his experiments with the furnace which provided
Bessemer with the idea for his later developments.

[13] British patent 2489, November 24, 1854.

[14] Bessemer, _op. cit._ (footnote 7), p. 137 He received
British patent 66, dated January 10, 1855.

[15] See James W. Dredge, "Henry Bessemer 1813-1898,"
_Transactions of the American Society of Mechanical Engineers_,
1898, vol. 19, p. 911.

These were described in his patent dated October 17, 1855 (British
patent 2321). This patent is significant to the present study because
his application for an American patent, based on similar
specifications, led to the interference of William Kelly and to the
subsequent denial of the American patent.[16] In British patent 2321
Bessemer proposed to convert his steel in crucibles, arranged in a
suitable furnace and each having a vertical tuyere, through which air
under pressure was forced through the molten metal. As Dredge[17]
points out, Bessemer's association of the air blast with the increase
in the temperature of the metal "showed his appreciation of the end in
view, and the general way of attaining it, though his mechanical
details were still crude and imperfect."

[16] See U.S. Patent Office, Decision of Commissioner of Patents,
dated April 13, 1857, in Kelly vs. Bessemer Interference. This is
further discussed below (p. 42).

[17] Dredge, _op. cit._ (footnote 15), p. 912.

[Illustration: Figure 1.--BESSEMER'S DESIGN FOR A CONVERTER, AS SHOWN
IN U.S. PATENT 16082. This patent, dated November 11, 1856, corresponds
with British patent 356, dated February 12, 1856. The more familiar
design of converter appeared first in British patent 578, March 1,
1860. The contrast with Kelly's schematic drawing in Fig. 2 (p. 42) is
noticeable.]

Experiments were continued and several more British patents were
applied for before Bessemer made his appearance before the British
Association on August 13, 1856.[18] Bessemer described his first
converter and its operation in some detail. Although he was soon to
realize that he "too readily allowed myself to bring my inventions
under public notice,"[19] Bessemer had now thrown out a challenge wh