62 



Popular Science Monthly 



mounted two large cams. Directly under 

 each of these there is suspended a foot. 

 As the shaft re\'olves, these feet are 

 lifted by the chains which are suspended 

 from a carr\'ing beam attached to the 

 cams and drawn forward and dropped on 

 the ground, whereupon the cam comes in 

 contact with them and its toothed 

 surface engages with similar depressions 

 on the foot. The whole machine is 

 raised and moved forward and gently 

 placed on the ground again, the motion 

 suggesting nothing more than a deliber- 

 ate walk. It is said that this additional 

 apparatus rep- 

 resents no more 

 weight than the 

 skids, planks 

 and other para- 

 phernalia made 

 use of in the 

 movement of 

 other excavat- 

 ing machines 

 when shifting 

 location. 



In this man- 

 ner the machine 

 will follow a 

 straight line. 

 When it is nec- 

 essary to change 

 its course for 

 any reason, the 

 walking appa- 

 ratus is stopped 

 at a point when 



the combinefl weight is resting on the re- 

 voK'ing platform under the center of the 

 machine. By making use of the latter 

 the machine is headed in the desired 

 direction, after which it will proceed 

 along its new course as long as desired. 

 When engaged in trench work, which is 

 of a progressive character, the machine 

 "walks" along as the work on the trench 

 is completed. This is a great advantage 

 in the reclamation ser\ice in which these 

 machines are employed by the Ck)vern- 

 ment instead of mule teams, which have 

 been eliminated b)- machinery. 



This excavator 

 is being used 

 with success by 

 the United 

 States Govern- 

 ment on one of 

 the great irri- 

 gation projects 

 of the arid 

 Southwest 



The driving- 

 shaft, the huge 

 cams and the 

 feet suspended 

 by chains from 

 the bars on the 

 cams are shown 

 in their rela- 

 tive positions 

 in the picture 

 appearing t o 

 the right 



Nations Bleed in Peace as Well as in War 



CANADA is awakening to the fact 

 that while she is bleeding openly 

 in war she has been bleeding quite 

 copiously in time of peace. In other 

 words, a comparison of the industrial 

 accidents and casualties with a list of the 

 casualties of the Canadian I'orces at the 

 front, reveals the information that 

 certain arts are as destructive, in pro- 

 portion, as certain forms of warfare. 

 I'urthermorc, Canada believes that she 

 has opened her heart and administered 

 with e\ery effort to those crippled in the 

 w.ir, but has given little attention to 

 (hose crippled in the arts of peace, 

 except to i)ay them a small indemnity. 

 Despite llie f.ut that improved ma- 



chinery has been installed in most 

 Canadian plants, cutting down appreci- 

 ably accidents formerly due to old 

 operating methods, the number of acci- 

 dents has continued to keep up. For 

 instance. Prof. F. H. Sexton of the 

 Technical Department of the University 

 of Nova Scotia, at Halifax, has kept a 

 careful record of killed or injured work- 

 men in the industrial arts. Comjiaring 

 his statistics for. say, December, I<)14, 

 with the same month for 11)15, one finds 

 that fifty-five men were killed as against 

 fift>-six of the year before, while two 

 hundred and sixt>-eight were injured as 

 ag.iinst two hundretl and se\'enteen of 

 the pri'N'ious vear. 



