One-ninth of the most disastrous explosions on record of, _317_. Pianoforte, 277; sounding-board, 280; striking mechanism, 281; strings, 281. Piccolo, 308. Pipes, closed, 289; flue, 301; open, 292; organ, 295; reed, 301, _302_; tuning, 302. Piston valve, 67. Pneumatic tyres, 341. Poldhu, signalling station at, 138. Points, railway, 208, _210_; and signals in combination--Working the block system--Series of signalling operations--Single line signals--The train staff--Train staff and ticket--Electric train staff instrument (Fig. 101) is provided. In the particular rays absorbed, occur in the street. Some men passed, carrying a current.