184 UNlVEliSITY OF VIRGINIA PUBLICATIONS 



Class 3. 



Grlass pipes, straight or of very eas}' curvature. New wrought iron 

 riveted pipes coated with asphalt under good conditions, straight or with 

 eas}' curvature. Wooden pipes of rectangular section, smoothljr planed, 

 well jointed and straight, with r = .3 feet. Straight unifomi open chan- 

 nels lined with neat cement smoothly trowelled of best construction. 



Class 4. 



Lead pipes, straight and smooth, or clean with easy curvature. New 

 cast iron asphalted pipes, straight or with very easy curves, under best 

 conditions. New wrought iron asphalted pipes in service mains under 

 best conditions. Open channels or flumes of carefully planed boards, 

 smooth joints, straight and of the best construction. Open channels of 

 uniform section and slope lined with neat cement of good construction. 



Class 5. 



New straight uncoated wrought iron pipe. New straight cast iron 

 pipe, smoothly coated with tar. Clean new cast iron asphalt coated in 

 ordinary service mains under best conditions, with perhaps few very easy 

 curves. Open channels or flumes of planed boards of good construction. 

 Cliannels lined with cement mortar % cement, % fine sand, straight and 

 of best construction. 



Class 6. 



Clean new straight cast iron pipes uncoated. Straight new wrought 

 iron cement lined pipe. New sheet iron riveted pipe, asphalted, straight, 

 under best conditions, diameters 6 to 18 inches. Channels and conduits 

 of brick work covered smooth with neat cement. 



Class 7. 



Ordinary service pipes of cast or wrought iron in good condition, 

 coated and uncoated, with easy curves, slight if any irregTilarities. Flumes 

 of unplaned boards of best construction. Brick conduits covered with 

 cement mortar % cement, i/3 sand. 



Class 8. 



Clean cast iron pipe mains with bends, few valves, slight irregularities 

 of ordinary service. Flumes and channels of sawed boards of good con- 

 struction. Conduits of brickwork of best construction, hard, smooth brick, 

 smooth mortar joints. 



