18 



U. S. BUREAU OF FISHERIES. 



Strength and weight of thread. 



A. HEMP. 



Test 1: 



Breaking load kilogram. 



Weight per meter gram. 



Breaking length kilometer. 



Test 2: 



Breaking load kilogram . 



Weight per meter gram. 



Breaking length kilometer. 



Test 3: 



Breaking load kilogram. 



Weight per meter gram. 



Breaking length kilometer. 



Test 4: 



Breakingload kilogram. 



Weight per meter gram. 



Breaking length kilometer. 



Test 5: 



Breaking load ^ kilogram. 



Weight per meter gram. 



Breaking length kilometer. 



B. COTTON. 



Test 1: 



Breaking load kilogram. 



Weight per meter gram. 



Breaking length kilometer. 



Test 2: 



Breaking load ^ kilogram. 



Weight per meter gram. 



Breaking length kilometer . 



Test 3: 



Breaking load kilogram. 



Weight per meter gram. 



Breaking length kilometer. 



Test 4: 



Breaking load kilogram. 



Weight per meter gram. 



Breaking length kilometer. 



Test 5: 



Breaking load kilogram. 



Weight per met er gram . 



Brealdng length kilometer. 



VI. 



Linseed 



oil. 



12.6 

 .821 

 1.5.3 



11.5 

 .704 

 16.3 



12.9 



.642 

 20.1 



.840 

 9.3 



(') 



727 

 9.6 



8.4 

 .734 

 11.4 



8.5 

 .710 

 12.0 



6.0 

 .660 



(^) 



VII. 



Spruce 

 cones. 



13.4 



.852 

 15.7 



12.4 

 .678 

 18.3 



12.6 

 .712 



17.8 



3.5 

 .700 

 5.0 



{b) 



VIII. 

 Tar. 



.987 

 10.9 



13.1 



.958 

 13.7 



11.9 

 .792 

 15.0 



9.3 

 1.030 

 9.0 



(«) 



IX. 



Que- 

 bracho. 



.720 

 17.4 



11.9 

 .686 

 J7.3 



12.7 

 .803 

 15.8 



5.0 

 .738 

 6.8 



C) 



8.5 

 .585 

 14.5 



8.6 

 .571 

 15.1 



8.5 

 .600 

 14.1 



3.7 

 .510 



W 



.974 

 8.0 



7.6 



.848 

 8.8 



8.4 

 .830 

 10.1 



6.8 

 .856 

 7.9 



(a) 



X. 



Zinc 

 chloride. 



8.1 

 .559 

 14.5 



8.2 

 .564 



14.6 



8.1 

 .590 

 13.7 



2.9 

 .495 

 5.9 



(») 



11.4 



.679 

 16.8 



8.1 

 .588 

 13.8 



6.6 

 .622 

 10.6 



7.2 

 .647 

 14.0 



3.0 



.487 

 6.2 



2.9 

 .523 

 5.5 



Of the methods that depend on tannins for their activity, Nos. Ill, 

 IV, V, VII, and IX, only two may be considered at all successful ; 

 they are Nos. Ill and IV, These two received identical treatment — 

 i. e., catechu wath copper sulphate and potassium bichromate — but 

 No. IV received a subsequent treatment with linseed oil. If judged 

 by the breaking strength alone, the linseed oil adds a very little ; but 

 if judged by breaking length, it is not so good as the previous one. 



Of methods of tanning nets this is additional evidence that the use 

 of a fixer or mordant, potassium bichromate, greatly increases the 

 preserving quality of tanning materials. 



The use of zinc chloride suggested itself to Lindeman because it 

 converts cellulose into so-called hydrocellulose and is used as a pre- 

 servative for railroad crossties. It is a failure for preserving nets. 



The nontannin preserving materials will be considered later. 



Another point about the table worthy of notice is that tannins 

 have an effect on hemp nets similar to that on cotton, but not so great. 



It should also be noted that Lindeman's paper appeared five years 

 earlier than Cunningham's paper, or that of Bull, next to be con- 

 sidered. 



