Popular Science Monthly 



905 



A Cattle-Guard Made of Cactus. 

 Horses and Cows Avoid It 



AN ingenius foreman on an Arizona rail- 

 l\ road recently conceived the idea of 

 using the cactus plant as a cattle-guard at 

 railroad crossings. The first, which was 

 planted a few 

 months ago, has 

 proved an un- 

 qualified success. 

 Not a single ani- 

 mal has at- 

 tempted to cross 

 it. As a matter 

 of fact, both 

 horses and cattle 

 are thoroughly 

 familiar with the 

 species of cactus 

 used, and fight shy 

 of it as they would 

 of a rattlesnake. 

 A frame of two 

 inch by six inch 

 timbers was placed 

 between the tracks. 



The cactus hedge for railroad crossings. The 

 frames at the side furnish a footing for workmen 



on edge and fitted 

 In the bottom of this 

 structure are a few inches of sand and gravel 

 in which the cactus plants were placed. 

 The cactus is very long lived, but as it 

 grows in abundance along the railroad, it 

 can be renewed if overlap small-* ^Expandedposmon 

 necessary. As the when gb^"T"^»x c: ™ :: jg 

 thorns will pierce an . ^"^v^-^t^ contracted^ 

 ordinary boot or A-^V 

 shoe, it was necessary 

 to place a piece of 

 timber along the bot- 

 tom bar of the fence 

 to allow employees 

 to cross. 



This is by far the cheapest form of cattle 

 guard in use on any railroad. 



A Collapsible Concrete Form Which 

 Works Like an Umbrella 



ANEW type of adjustable and col- 

 lapsible steel concrete form works 

 on the principle used in constructing the 

 ribs of an umbrella. The form is made in 

 two types, one 

 for circular cul- 

 verts and the 

 other for small 

 bridges with 

 semi -elliptical 

 arches. Both 



types are collap- 

 sible for greater 

 ease in shipment 

 from point to 

 point or for move- 

 ment ahead, as 

 each section of 

 culvert or bridge 

 is concreted and 

 hardened in place. 

 Each type is also 



adjustable, the culvert type from twenty to 

 forty inches in diameter and the bridge 

 design from spans of six feet to forty feet. 

 The fact that both units are adjustable with- 

 in such comparatively wide limits greatly 

 reduces the cost of the forms used because 

 of their reduction in 



Threaded T bar 



Diagram showing the principle on which the 

 diameter of the form is increased or decreased 



number. With the 

 ordinary wood types 

 a special form would 

 have to be made for 

 each diameter culvert 

 or each differently 

 spanned bridge. Be- 

 cause both types are 

 of steel instead of 



wood, they last indefinitely and reduce the 

 cost of form construction. 



!B» ' ilsi 



Turning the hand-wheel adjusts the 

 angle of inclination of the radial arms 



The adjustable bridge form. The over- 

 lapping surface plates are forced in or out 



