allings, _Elevators_,
Chicago, 1916, p. 82.)]

The success of this system initiated a sizable industry in England, and
the hydraulic crane, with many modifications, was in common use there for
many years. Such cranes were introduced in the United States in about 1867
but never became popular; they did, however, have a profound influence on
the elevator art, forming the basis of the third generic type to achieve
widespread use in this country.

The ease of translation from the Armstrong crane to an elevator system
could hardly have been more evident, only two alterations of consequence
being necessary in the passage. A guided platform or car was substituted
for the hook; and the control valves were connected to a stationary
endless rope that was accessible to an operator on the car.

The rope-geared hydraulic system (fig. 13) appeared in mature form in
about 1876. However, before it had become the "standard elevator" through
a process of refinement, another system was introduced which merits notice
if for no other reason than that its popularity for some years seems
remarkable in view of its preposterously unsafe design. Patented by Cyrus
W. Baldwin of Boston in January 1870, this system was termed the
Hydro-Atmospheric Elevator, but more commonly known as the water-balance
elevator (fig. 12). It employed water not under pressure but simply as
mass under the influence of gravity. The elevator car's supporting cables
ran over sheaves at the top of the shaft to a large iron bucket, which
traveled in a closed tube or well adjacent to and the same length as the
shaft. To raise the car, the operator caused a valve to open, filling the
bucket with water from a roof tank. When the weight of water was
sufficient to overbalance the loaded car, the bucket descended, raising
the car. On its ascent the car was stopped at intermediate floors by a
strong brake that gripped the guides. Upon reaching the top, the operator
was able to open a valve in the bucket, now at the bottom of its travel,
and discharge its contents into a basement tank, to be pumped back to the
roof. No longer counterbalanced, the car could descend, its speed
controlled solely by the brake.

The great popularity of this novel system apparently was due to its smooth
operation, high speed, simplicity, and economy of operation. Managed by a
skillful operator, it was capable of speeds far greater than other
systems could then achieve--up to a frightening 1,800 fee