CLAY WORKING INDUSTRIES. 137 



1. N. U. Walkers, sewtv pipe clay, Columbiana county Lord. 



2. Freeman's sewer pipe cla} r , Jefferson county Lord. 



3. Island Siding Clay ftfferson county, fit for sewer pipe Lord. 



4. Same clay, another sample Lord. 



5. E. Palestine paving brick clay, Upper Fresport horizon Lord. 



6. Massillon Fire Brick & Stone Co., mixture of fire clay with shale 



and surface clays used for paving bricks Lord. 



7. Toronto sewer pipe clay, top Chemist not known. 



8. " " " " bottom ' " " 



9. Average, top and bottom, Toronto " " 



10. Empire sewer pipe clay " " 



11. Elliottsville sewer pipe clay " 



12. " " " " " 



13. Croxton Run sewer pipe clay , " " " 



14. N. U. Walker's sewer pipe cla5' Reed. 



These analyses were for the most part collected from the previous 

 report on clays and from other sources. Only two analyses, Nos. 5 and 

 6, were made for the present investigation, and from samples which are 

 valuable or imporrant. 



The series of analyses from the seventh onward were made from the 

 excellent sewer pipe clays which are worked along the Ohio valley from 

 Toronto northwards, but they lose force from our ignorance as to how 

 samples were taken and to whom the work is to be attributed. It is likely 

 that the analyses indicate clays of greater purity than the results would 

 show if the analyses could have been made from good samples of the 

 finely ground material. However, the results as they are, are interesting 

 and show far better thau mere description the general character of the 

 vitrifying fire clays. 



The average of these analyses shows a clay composed of 



93.41 per cent, clay and sandy matters 

 with 5.65 per cent, of iron and fluxes. 



99.06 



This shows on being calculated an oxygen ratio of 



2.40 acid to 1 base, and 

 7.7 alumina to 1 flux. 



which shows a clay more fusible than the stone ware clays and yellow 

 ware clays, but far less fusible than the shales. 



These indications are borne out by the facts, as the clays of the Ohio 

 River Valley, while they vitrify fairly well in the shape of sewer pipe 

 where the thickest section of the ware is not to exceed 2 inches and most 

 of it less than 1£ inches, when made into paving bricks or blocks, are 

 very difficult to vitrify sufficiently to stand a good absorption test. 



This will be more fully discussed in the paving brick tests later in 

 this article, but suffice it to say that a clay of such a composition as this 

 average shows, would not be suitable for paving material without the 



