Popular Science Monthly 



729 



What's a Dreadnought? And the 

 Purpose of a Dreadnought? 



IX these days of stirring events and na- 

 tion-wide discussions of preparedness, 

 naval terms are frequently confused in 

 ordinary conversation. 



It is generally known that the displace- 

 ment of battleships — that is, their actual 

 weight in tons — has increased by leaps and 

 bounds from the original five or 

 six thousand tons to the present 

 day battleships of up- 

 wards of thirty thou- 

 sand tons. The term 

 "dreadnought," how- 

 ever, did not come 

 into use until 1906, 

 when the British Ad- 

 miralty evolved what 

 is known as the first 

 all big gun ship. Prior 

 to that time nearly all 

 battleships were 

 armed with four large 

 guns of ten, twelve 

 and sometimes thir- 

 teen-inch caliber, and 

 from twelve to four- 

 teen smaller guns, 

 var>'ing in diameter 

 from six to nine 

 inches. The British Admiralty 

 adopted the bold plan of building 

 a vessel armed with a main bat- 

 tery of ten 12-inch guns and no 

 guns of smaller caliber. This 

 vessel was named the "Dread- 

 nought," and hence became the 

 forebear of the type of ships 

 armed with big guns exclusively. 

 The departure was copied by 

 all the great naval powers, and 

 the race in size and number of 

 guns has gone on uninterrupt- 

 edly, so that this countr>^ now is 

 building battleships like the 

 "Mississippi" of 32,000 tons dis- 

 placement and armed with twelve 

 14-inch guns. A new term has 

 been found necessar\- in the pop- 

 ular mind to describe these leviathans of 

 over 25.000 tons; they are called "super- 

 dreadnoughts." Battleships built just be- 

 fore the time of the "dreadnought," but 

 which did not carry all big guns in their 

 main batteries, are termed "pre-dread- 

 noughts." "Battle cruisers" while not so 

 heavily armored as dreadnoughts possess 

 much greater speed. 



A^ 



A Non-Skid Automobile Device 

 Without Chains 



NEW non-skid device consists of two 

 prong-like bars attached to the rear 

 axle of the automobile and operated by a 

 hand lever at the driver's seat. The prongs 

 are mounted in ball-and-socket joints in 

 clamps around the axle between the spring 

 fastenings and the brake drums. When 

 out of action the prongs are held 

 1 horizontally and entireh' out of 

 contact with the ground. 

 Should the vehicle be- 

 gin to skid, they may be 

 revolved and thus 

 brought down into con- 

 tact with the ground 

 and against the tires. 

 Each prong is made of 

 two parts. The flat 

 but narrow bot- 

 tom shoe -like por- 

 tion telescopes 



The non-skid device is 

 compKjsed of two bars 

 attached to the rear axle 

 and controlled by a spring 



/^DIRECTION OF 5WD 



The two prong-like bars 

 are op>erated by a hand 

 lever at the driver's seat 



SKJD3H0EINC0KTACr 

 WITH TIRE. 



How the device 

 works when the 

 vehicle begins to skid 



into the upper end and has a 

 certain upward movement when 

 a spring in the telescoping section 

 is compressed. 



The prongs are lowered when 

 the vehicle begins to skid. The 

 one on the side toward which the 

 vehicle is skidding, swings in- 

 wardly to an inoperative position 

 due to the ball-and-socket joint 

 and the yielding shoe. That on 

 the other side, however, comes in 

 contact with the tire. As the 

 shoe scrapes over the ground the 

 tire forms a buffer until the vehicle's side 

 motion is stopp>ed. The shoe is forced out- 

 wardly against the tire by a spring-retained 

 lever pressing against the upper part of the 

 prong. The yielding shoe serves to pro- 

 tect the prong from injury should it hap- 

 pen to strike on a street car rail. Other- 

 wise the skidding momentum might be 

 sufficient to break it. 



