445 



towns or in the rural districts. To give some idea of tlie 

 gigantic nature of the undertaking, on which the safety of the 

 tunnel depends, one lias only to inspect the building where the 

 engines are at work in connection with the Sudbrook spring, 

 which has given the authorities so much trouble. Here sS 

 steam cylinder-s each 5ft. lOin. in diameter, work day and night 

 (at this, time it was necessary to work four only), it may be said 

 almost noiselessly, so smooth is their action, drawing by the 

 united efforts of "plunger" and "bucket," 2,160 gallons per 

 stroke, as the following table shows : 



Passing on through the boiler house the great fan, 40ft. in 

 diameter, was visited, so necessary to the ventilation of the 

 tunnel. A minute or two was quite sufficient for the small 

 parties of six at a time to witness its murky revolutions, and to 

 be smirched with the black greasy residuum from the vitiated air 

 that was drawn up from below. Time was all too short to dwell 

 much on these works, and a quarter of an hour was alone 

 permitted to a small party of four at a time to descend in cages 

 to the bottom of the shaft, whence the Sudbrook spring is 

 pumped 180 feet below the surface. The huge pumps slowly and 

 methodically working up and down in the darkness, just rendered 

 visible by the workmen's lamps, and the noise of the running 

 water underfoot contributed much to the weird uncanniness of 

 the scene. An iron door slowly moving on its hinges admitted 



