426 



Popular Science Monthly 



A Safety Box for Carrying Blasting 

 Caps in the Field 



WE are becoming so well acquainted 

 with high explosives that we play 

 with them as if they were toys in our hands. 

 In a single year enough explosives are left 

 in public conveyances by thoughtless people 

 to blow up a dozen mines. In the New 

 York subway, for instance, there have 

 been found cans of nitroglycerine, sticks of 

 dynamite, bombs of all 

 sorts and descriptions, and 

 other explosives in sufficient 

 quantities to rock the whole 

 island were they "touched 

 off." All of which goes to 

 prove that some people 

 think no more of toting a 

 death-dealing article about 

 town than carrying an um- 

 brella. Evidently the pow- 

 der-shy days have passed. 



Not long ago a box filled 

 with one hundred blasting 

 caps was thrown over a 

 fifty-foot embankment in- 

 to a quarry, where it 

 bounced around on the 

 rocks with no resultant 

 explosion. The fact that 

 the caps did not explode 

 was due to the box in 

 which they were 

 packed — a safety 

 box for carrying 

 blasting caps in the 

 field. Although 

 blasting caps and 

 dynamite never are 

 carried in the same 

 receptacle, blasting 

 caps have caused 

 some serious explo- 

 sions in the past. 

 Some miners would 

 rather handle a car- 

 load of dynamite 

 than a box of blast- 

 ing caps. 



The new safety 

 box shown in the 

 photograph contains 

 one to carry electric 

 the other to carry regular blasting caps for 

 use with fuse. The box is made of oak with 

 a top of pine. It is lined with felt obtain- 

 able at harness shops. The cap board is 

 removable but it fits snugly on, the space 

 between it and the caps being padded out. 



.... Jhii_ ' 



The box can fall off a wagon and cause no 

 more damage than if it contained spaghetti 



two compartments, 

 blasting caps and 



The Race Between Nature and the 

 Scientific Motion-Picture Camera 



SOME day the scientific camera-man 

 is going to photograph for us the 

 thousands of movements in nature which we 

 have never been able to see because of their 

 lightning swiftness. This camera-man will 

 have a camera capable of taking five 

 thousand pictures per second — or possibly 

 a camera which takes a continuous motion- 

 picture with no revolving shutter and inter- 

 mittent film movement. He will, 

 in fact, be able to photograph 

 the fastest movements in 

 nature. 



In Germany a picture 

 has been taken in one 

 ten-millionth part of a 

 second. The ordinary 

 motion-picture camera 

 takes sixteen pictures a 

 second. This means that 

 a considerable portion of 

 the action is not photo- 

 graphed. In filming a 

 motion-picture drama 

 this loss means nothing; 

 but in scientific research 

 the films would be worth- 

 less. At present the 

 fastest motion-picture 

 camera takes pictures at 

 the rate of two thousand 

 per second. Naturally 

 this camera misses 

 very little of the 

 action and shows us 

 many wonders of 

 nature which the 

 human eye has 

 never looked upon. 

 For instance, take 

 the beat of the hon- 

 ey bee's wing — one 

 of the most rapid 

 movements in na- 

 ture. A picture 

 taken in a sixteenth 

 of a second misses it 

 completely. But a 

 new camera in which 

 the picture is taken by an electric spark 

 has given us the first view of a bee in flight. 

 A bee was launched almost upside down 

 before the camera, the film showing its 

 efforts to right itself. It regained its equi- 

 librium so quickly that no eye could pos- 

 sibly have followed its movements, but 

 twentysharf>lyfocussed pictures were taken. 



The box carries one hun- 

 dred blasting caps for 

 work. It is impossi- 

 for them to explode 



