Page:Popular Science Monthly Volume 88.djvu/859

 Popular Science Monthly

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��This slides along the bottom of the trench and supports the rear end of the wheel frame work. Depth of dig- ging is controlled by raising or lowering the front end of this framework, the rear por- tion of course riding along on the "shoe" according to the depth of the front end. A special feature of this "shoe" is that a man can ride on it laying tile or pipe as fast as the digging progresses.

Many widths and depths of trenches can be cut by the machines. Some have been made six feet wide and fif- teen feet deep. One machine dug two hundred rods of eleven and one-half inch trench thirty inches deep in a ten-hour day, and another dug a thousand feet of twenty-inch trench five and one-half feet deep in the same time. Small boulders, tree roots, and similar barriers offer no great obstruction, and the machines accomplish work under difficult circum- stances with a celerity that prising.

Various modifications of the chain- type and wheel-type have been made to fit special conditions. These relate largely to the shape of buckets used, since digging an open trench in sandy soil re- quires a far different kind of bucket than

���"Caterpillar" wheels enable the big machine to travel over soft ground

��IS sur-

��making a clean-cut channel in hard clay. To enable the machines to travel o\er wet, soft ground "caterpillar" wheels are used.

��Traveling by Parcel Post 'T^HOUGH our parcel post "

��IS a enabling us to

��won- send

���In a ten-hour day this machine will do the work of two hundred men

��derful system, all kinds of strange things by mail, the English system can do one thing which we have, as yet, not attemped.

An Englishman who was in a hurry to reach a part of London with which he was unfamiliar, called at the general post oflice to consult a directory. Upon ex- plaining his case, the clerk gave him the starlHng information that he could go by parcel post for the payment of threepence a mile.

He was accordingly placed in charge of a messenger who took him to his des- tination. The boy carried a printed slip on which was written "Article required to be delived" with a description of the parcel following.

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