Page:Popular Science Monthly Volume 91.djvu/875

 Popular Science Monthly

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��"Let There Be Light— Enough to Blind the Enemy," Said Cadorna

THERE have been thrilling happenings galore in this war of wonders, but noth- ing more dramatic has been reported than the manner in which the Italians under Cadorna, by a piece of engineering dare- deviltry, crossed a great gorge in the Alps and brought their troops, guns and entire equip- ment right up under the Austrians' noses without losing a man.

The feat was accom- plished by sheer audacity — made possible by blind- ing the enemy with floods of light from searchlights strung along the Italian side of the gorge and con- centrated on the Aus- trians all during the momentous night, so that they were unable to see what the Italians were do- ing. When the morning dawned, the sun revealed a number of bridges which the daring Italians had erected over the terrible chasm during the night.

Naturally the Austrians suspected that something was going on while the powerful searchlights were making noonday glare all around them and leaving the Italians and the surrounding country wrapped in mid- night blackness. They fired their guns ceaselessly, but the booming only served to conceal the noise of the bridge-building.

The engineers had to drop their pontoon boats down a forty-foot wall on wooden skids, then join them across as treacherous a stream of running water as was ever en- countered anywhere, plank them over so that the troops could cross, and provide ladders to enable the troops to scale the precipice on the Austrian side. Time and again the current swept the boats away before they were properly joined. But in the morning the Austrians fell back in con- sternation before the entire Italian unit, not a hundred yards away.

���The Details of the Valve-Turning Device

The valve-rotator consists of four main parts: a threaded boss slipped over the valve stem near the bottom; a hollow sleeve rigidly attached to the cylinder water-jacket and internally threaded to fit the thread of the boss; a ball-bearing joint the bottom half of which is attached to the valve push-rod and the upper half of which has a small projection with saw teeth to contact similar teeth on the bottom of the boss around the valve stem; and a coil-spring between the hollow sleeve and the ball-bearing joint

��Turning Valves on Their Seats Automatically

A SIMPLE device has just been designed and patented for the purpose of auto- matically rotating the valves of gas engines on their seats while the motors are running, thereby bringing a different portion of the valve head and stem into the path of the flame on each up and down stroke. This rotative action is positive and reduces the pitting on the valve seat or valve head, this in turn requiring less valve grinding and making for less fuel and oil wasted, since it is impossible for either to work its way past the valve seat. As shown in the dis- assembled unit pictured and the cross-sectional view, the valve rotator consists of four main parts, a threaded boss slipped over the valve stem near the bottom ; a hollow sleeve rig- idly attached to the cylinder water-jacket and internally threaded to fit the thread of the boss ; a ball-bearing joint the bottom half of which is attached to the valve push-rod and the upper half of which has a small projec- tion with saw teeth to contact with similar teeth on the bottom of the boss around the valve stem ; and a coil-spring between the hollow sleeve and the ball-bearing joint.

In operation, the upward movement of the valve push-rod causes the teeth in the ball-bearing joint member to mesh with those on the bottom of the boss, the angularity of the teeth tending to cause the valve stem to move round against the resistance of the coil-spring. As the valve stem drops, the spring brings the ball- bearing joint back to its original position as the teeth are withdrawn from mesh. The next upward movement forces the valve round on its seat a little more until by a succeeding upward stroke it has made a complete revolution on its seat.

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