Page:Popular Science Monthly Volume 92.djvu/877

 Popular Science Monthly

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��^Catch operMrvg ring

���and alone. On contact patrol, planes fly very low and have done such effect- ive work particularly with their ma- chine-gun fire, that the Germans have found it necessary to dig bullet-proof trenches alongside the roads on which their troops march. At the alarm, the regiments dive for these trenches where they are com- paratively safe.

Generally five planes are assigned to a con- tact patrol squadron. They fly in the usual V-shape formatic^. Once over the lines, their work commences. They remind one of hawks hovering over a chicken yard. Eagerly the pilots and observers scan the ground below, undaunted by the hail of lead poured up at them from machine-guns and "Archies."

���will be hidden in them with the result that perhaps one or more planes of the squad- ron will be brought down by their fire. Hostile ammunition and gasoline depots, headquarters, railway junctions, detrain- ing stations and aircraft hangars are all objectives for the pilots of a contact pa- trol squadron. It may be that there is a de- tachment of enemy en- gineers busily engaged in preparing the site for a new battery or building a bridge. If seen, rest assured that the planes will give them a warm reception.

��Clvjmp of steel ^rows

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��Submarine Saws for Water Weeds

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��What's That? A Regi- ment of Germans ?

��What the observers in the machine want to see most is a train or railroad or road-bridge. As soon as they see one, down they swoop. One after the othei* lets go a load of bombs and climbs again. The observers note the damage, etc. Suppose they see a regi- ment marching rapidly towards the front. In a fast glide, they descend almost on top of the startled soldiers. The machine- guns mow the Germans down, and often one plane of the squadron, flying higher than the rest, releases several clumps of the steel arrows. If there are no safety tren- ches at the side of the road, it is pos- sible that al- most the whole regiment may be \\iped out. Should there be trenches, no doubt machine-guns

��These arrows, dropping from a great height, have consider- able penetrative force, but a steel helmet affords Drotection

���The saw, from loO to 300 feet long, cuts the weeds; a wooden grating collects them and a rake removes them

��SUBMARINE saw is used to clear weeds from irri- gation canals on the project of the United States Reclamation Ser\ice at Orland, Cali- fornia. It is five-six- teenths of an inch wide, one-fiftieth inch thick, and the teeth are spaced seven-sixteenths of an inch apart. It is made of special steel in flat, flexible, tape form and has toothed edges. Two men. one at each end, operate the saw by means of ropes, starting at the lower end of the section to be cleared and working up-stream. The saw is placed diagonally across the stream, one man keeping slightly ahead of the other. It is held at the bottom of the canal by iron weights placed at intervals of about three feet. To remove the weeds, planks are placed across the banks, about six inches above the sur- face. Slanting wooden pieces project into the water form- ing a grating which catches the mo^^Ti weeds.

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