Figure 12. — Natural sponges abrasion loss, statistically 

 reliable within 50 percent probability . 



Type of sponge 



Grade 



Rock Island 





3heet)swool 



1 Form 





2 F 





3 F 





h F & Cut 





1 Cut 





2 C 





3 C 



Inshore Sheepswool 



1 F 





2 F 





3 F 





k-F 





1 & 2 C 





3 c 



Florida Yellow 



1 F 





2 F 





3 F 





1 C 





2 C 





3 C 



Anclote Grass, 



2 C 



Dark 



3 C 





k c 



Anclote Grass, 



1 c 



Pale 



2 C 





3 c 



Hudson Grass, 



1 c 



Dark 



2 C 





3 c 



Hudson Grass, 



1 c 



Pale 



2 C 



Mediterranean, 



1 F 



Bengasi 



2 F 



(or Hard) 



3 F 





k F & C 





1 C 





2 C 





3 C 



Mediterranean, 



1 F 



Deenwater 



2 F 



(or Soft) 



3 F 





h F & C 





1 C 





2 C 





3 C 



Florida Key Wool 



6 E 



Cuban Sheepswool 



6 E 



Grams lost* 



' ' ' i.obc' ' ' ' ' 



2.0'0C 



Per 5-25 square inch for a 0.22 pound per square inch load over 5^2 foot 

 path on wet 400 A silicon carbide paper. 



So 



