London is servedby three transit roads - the Nortk London rrailway, which traverses the northorn subnrbs above the houses, and is twelve miles long ; the Metropolitan DisUict railway, seven miles long underground ; and the Metropolitan railway (the first built), whieh is thirteon miles underground. There are a few branch lines in addition to these, and tho main liues are connected with the principal liues of railway running into London at the soveral largo termini. Tho Metropolitan cost $3, 000,000 ft milo, or $39,000000 in all. Tho Metropolitan District cost $3,700,000 per mile, or $25,000,000 for the whole road ; and the North London the smaller sum of #1,560,000 per milo, or $18, 720,000 in all. Thus tho thrco roads, ruuning thirty-two miles, cost $83,620,000. Tho bulk of the paesengers on all these linea are third-class - that is, artisans, Jaborors, and the poorer classes going to and rriturning from their work. In tho aggregate the percentage of passongers is one-tenth first-class, one-fifth sociiud-class, and sevcn tenths thirdclass. Tho working expenses of each line vary - the highost, an underground line, beiug 55 per cont. of the receipts, and the lowest, also aa underground, boing 39 per cent. This latter is the flrst railway of the kind built, and paj s abont 4 per cent. on its capital. The highest pays 4J per cent., the loweet about 2 per cent.