drive. The important "automatic" feature of Newall's system was retained but the worm drive ensured that the brakes did not act too fiercely when released. It was Fay's version of the system that the company entered for the Newark brake trials of June 1875, where a moderate performance, usually in the mid position of the eight systems on test, was achieved. The chain brake, in which a chain was connected continuously along the bottom of the train. When pulled tight, it activated a friction clutch that used the rotation of the wheels to tighten a brake system at that point; this system has severe limitations in length of train capable of being handled (as braking strength was considerably weaker after the third car), and of achieving good adjustment (give the slack that pin couplers required, which a fixed-length chain could not account for). In the United States, the chain brake was independently developed and patented by Lucious Stebbins of Hartford, Connecticut in 1848 and by William Loughridge of Weverton, Maryland in 1855. The British version was known as the Clark and Webb Brake, after John Clark, who developed it throughout the 1840s, and Francis William Webb, who perfected it in 1875. The chain brake remained in use until the 1870s in America and 1890s in the UK. The Heberlein brake is a notable variation on the chain brake popular in Germany, using an overhead cable instead of an underlinked chain. Hydraulic brakes. Actuating pressure to apply brakes was transmitted hydraulically (as with automobile brakes). These found some favour in the UK (e.g. with the Midland and Great Eastern Railways), but water was used as the hydraulic fluid and even in the UK "Freezing possibilities told against the hydraulic brakes, though the Great Eastern Railway, which used them for a while, overcame this by the use of salt water" The simple vacuum system. An ejector on the locomotive created a vacuum in a continuous pipe along the train, allowing the external air pressure to operate brake cylinders on every vehicle. This system was very cheap and effective, but it had the major weakness that it became inoperative if the train became divided or if the train pipe was ruptured. The automatic vacuum brake. This system was similar to the simple vacuum system, except that the creation of vacuum in the train pipe exhausted vacuum reservoirs on every vehicle and released the