412
EXPOSITION AT VIENNA.
balustrade ran across the front, over which the working of the boilers could he easily studied.
The boilers themselves embraced all the prominent types, cylinder, flue, tubular, and those known as tubulous, or containing the water within small tubes. The cylinder boilers were mostly variations of what is known as the French, or elephant, which consists of one cylinder of large diameter, connected by large tubes, or pipes, with two more smaller ones above it.* The flue-boilers were best represented by the Galloway and Adamson exhibits. The former are well known by the cross-tubes, of a long tunnel shape, which extend across the flues. The latter are similar, except that the cross-tubes are not all perpendicular.
The tubular boilers were represented by one of the ordinary American type, in our department, contributed by Pitkin & Co., of Hartford, Ct., by some of a nearly similar character in use by the Germans, and by those exhibited by Cater & Walker, of England. The latter received the products of combustion after they had passed under the boiler into a smoke-box in the body of the cylinder near the rear end, w'hence they passed by a number of longitudinal tubes to another smoke-box near the front, and were finally delivered into the smoke-stack, at the rear, by another series of tubes.
Among: the tubulous boilers were those of Howard & McNichol among the English, and Belleville among the French. The McNichol is used particularly in connection with paper-pulp machinery, and was designed for the purpose of carrying the very high pressures desirable.
One striking variation from our practice was in the large diameters of the boilers used, especially by the English. The boilers spoken of above (Galloway’s, Adamson’s and Cater’s) were five feet in diameter.
Another point, especially marked among the Germans, was the manner in which they added to their main boilers supplementary boilers, or heaters, into w T hich the water first passed. In some cases small boilers; in others, coils or
* A number of these boilers are in use in one of our large mills in Massachusetts. Of them the Agent said that, in a test, they showed the poorest results of any boilers tried, but in practice had proved about the most economical and the least trouble some.