j|. 607, U. S. Dept. of Agriculture 
Plate X. 
Penetration in Paving Blocks. 
No. 1 blocks treated with creosote No. 4. No. 2 blocks treated with 75 per cent creosote No. 4 and 
25 per cent tar No. 5. No. 3 blocks treated with 50 per cent creosote No. 4 and 50 per cent tar 
No. 5. No. 4 blocks treated with 25 per cent creosote No. 4 and 75 per cent tar No. 5. 
