620 



PATENTS. 



engineer officers. Capt. McEvoy believes that 

 his device is applicable for danger signals near 

 exposed coasts. 



Clothes-line Pulley. An improvement has 

 been patented by John J. Leuzinger, of West 

 New Brighton, N. Y. The pulley, as shown in 

 section and in perspective, is deeply grooved 



CLOTHES-LINE PULLEY. 



and pivoted in a block which has a semicircular 

 recess in its under face. When in position for 

 use the block revolves in a horizontal plane, and 

 the line, which is continuous or endless, carries 

 clamps fixed at convenient distances and fitted 

 so that they will hold the clothes hung out to 

 dry and permit at the same time the free revolu- 

 tion of the line throughout its entire length. It 

 would seem to be a device eminently adapted to 

 the convenience of dwellers in city blocks. 



Improved Wheel-Tires. The march of im- 

 provement in the construction of bicycles and 

 velocipedes of all kinds is so rapid that it is al- 

 most impossible to keep up with them from year 

 to year. In construction it would seem that the 

 bicycle frame has reached almost the limit of 

 combined lightness and strength, and yet not 

 a year passes that does not see some decided 

 advance in both these particulars. The most 

 noteworthy improvement of late years has cer- 

 tainly been the pneumatic tire. It is fresh in the 

 recollection of every one how very clumsy this 

 device seemed at first the bulky rubber tire 

 looking excessively awkward and heavy by com- 

 parison with the light cushioned tires to which 

 the public had become accustomed. The pneu- 

 matic tire is in effect simply a circular section of 

 rubber hose, made exceedingly strong either by 

 metallic or canvas linings and successive coat- 

 ings of the toughest rubber. This is stretched 

 around the periphery of the wheel, and the effect 

 of it is to render smooth even a comparatively 

 rough road. The main difficulty lies in providing 

 a practically tight valve wherewith the wheel- 

 tire can be inflated. There is always some 

 leakage, and continual pressure will force the 

 air through several thicknesses of India rubber 

 no matter how carefully they are put together. 

 The pneumatic tire was originally an English 



invention, but it has been perfected in this coun- 

 try, and the best valves, it is now.admitted, are of 

 American construction. With these tires it is 

 possible to use roads which were heretofore im- 

 practicable to wheelmen ; and there are cases on 

 record where a good rate of speed has been main- 

 tained over railroad ties, the pneumatic tires so 

 far reducing the shock as to render progress 

 comparatively comfortable. Not only has the 

 pneumatic tire been applied to bicycle wheels, 

 but it is rapidly making its way to the trotting 

 race track, and some of the most surprising re- 

 sults have been attained by applying the tire to 

 ordinary wagon wheels. It was thought, when 

 bicycles first made their appearance, that their 

 introduction would result in great improvement 

 on the ordinary country roads ; this has already 

 come to pass, as instanced by measures taken in 

 many of the States. The mission of the bicycle 

 is evidently not altogether athletic, if it can ex- 

 tend its influence so as to improve our public 

 roads and the vehicles' driven over them. 



The vast number of ingenious devices that 

 have been brought to bear upon this problem of 

 elastic wheel-tires is simply amazing. A mere 

 list of them would be too long to be printed 

 here. Suffice it to say that coiled tubes inside 

 the larger tube, springs of metal arranged around 

 the circumference of the wheel, small inflated 

 balls of rubber, and scores of other similar de- 

 vices, have been patented. 



Carpenter's Square. An improvement in 

 this familiar implement is shown in the illus- 

 tration. The two arms are 

 pivotally secured at the angle, 

 so that one of them may be 

 swung through an arc of 90. 

 The pivots and bearings are 

 such that there is a minimum 

 of strain and small liability 

 of wear to the point of inac- 

 curacy. The longer arm of 

 the square has a shallow re- 

 cess in which is pivoted an 

 extension of the shorter arm, 

 and the adjustment is main- 

 tained by a set screw whereby 

 the arms may be locked at 

 any desired angle. As shown 

 in the illustration, the two 



CARPENTER'S SQUARE. 



arms lock automatically when brought into the 

 ordinary position for use as a square. One obvi- 

 ous ad vantage of this tool is that it can be folded 

 together so as to go into an ordinary tool box. 

 The inventor is F. W. Palmer, of New York. 



