111. Read the height of the sponge by means of the half -inch marks 

 on the vertical strip of aluminum and the horizontal lines marked on 

 the vertical back board, 



15 • Record the height of the sponge as Hs, the height of the un- 

 compressed sponge. 



16. Multiply the smallest diameter by the largest diameter and 

 then by O.Uj that is, D s x E>i x O.iu (Note: The answer gives the weight 

 in pounds needed to apply a pressure of 1/2-pound per square inch to 

 the sponge,) 



17. Multiply the answer obtained in step 16 by the height of the 

 sponge and then by 1,3; that is (Dg x Di x O.U) x H s x 1,3, (Note: 

 the product obtained is approximately equal to-jf^ .) 



~5~ 



18. Record the answer obtained in step 17 as being V, the bulk 

 volume of the sponge, 



19. Subtract the weight of the top can or pressure vessel from 

 the answer obtained in step 16, 



20. Add to the pressure vessel a weight in pounds equal to the 

 answer obtained in step 19, 



21. Place the sponge in the measuring basket, 



22. Lower the measuring basket into the water, submerge the sponge, 

 and press out all the bubbles again, 



23. Raise the measuring basket to the rest position, 

 2li, Slowly lower the pressure vessel onto the sponge, 



25. Determine the volume of water remaining in the sponge by 

 reading the copper gauge, 



26. Record the answer obtained in step 25 as being W r , the water 

 remaining in a sponge when a pressure of 1/2-pound per square inch is 

 applied, 



27. Observe the height of the sponge and record the height as 

 being He, the compressed height, 



28. Quickly raise the pressure vessel from the sponge and im- 

 mediately observe the height of the sponge, 



29. Record this height at being Hp, 



30. Wait 2 minutes and again observe the height, 



31. Record this height as being Hp, the height corresponding to 

 the permanent set, 



ko 



