RIVETING. 



143 



joining the plates. The present method of lapping both hori- 

 zontal and vertical seams is awkward and unmechanical, and 

 belongs more to the methods of the village blacksmith than 

 those of precise and scientific mechanism. They should 

 rather be like the accompanying sketch, taken from a paper 

 read before the New England Water-works Association in 



1893. 



" In this sketch the horizontal seams are lapped, and the 

 vertical seams made with butt-straps. This is a perfectly pre- 



r~" 



CALKING JOINT 



QQiQCO 



00^1 



CALKING JOINT- 



CALKING JOIWTV. 



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o 



FIG. 39. METHOD OF JOINING PLATES IN STEEL. 



cise method, and requires no beating down or drawing out of 

 the plates, and, in my opinion, would really cost no more than 

 the old way. I use it now on plates over in. in thickness, 

 but should prefer to use it on all thicknesses." 



Notwithstanding Mr. Coffin's opinion as to the relative 

 cost, builders of stand-pipes will make quite a difference in 

 the cost of a particular structure if the butt-joint is required, 

 as it seems perfectly proper that they should do, for the rea- 

 son that a butt-joint requires twice as many rivets as a lap- 

 joint, because in the lap the rivet passes through both the 

 plates, whereas in the butt-joint it passes through only one, 

 so that there is necessarily an additional cost for punching or 

 drilling, rivets, and driving. 



