Below is given analyses of English clays used for the manufacture of enameled brick and glazed sanitary ware. For these analyses I am indebted to "The Manufacture of Glazed Bricks and Glazed Sanitary Ware," published by H. Grevllle Montgomery:

—No. 1 Strong.—

  

Silica (SiO2) .........................................................................

70.55

Alumina (A1203).........................

20.27

Oxide Iron (Fe2O3).......................

1.45

Lime (CaO).............................

.75

Magnesia (MgO) ..................................................................

.24

Water ....................................................................................

6.52

Organic Matter .....................................................................

.22

   
 

100.00

—No. 2 Strong.—

  

Silica..................................

76.03

Alumina ...............................................................................

16.55

Oxide Iron ............................................................................

1.18

Lime .....................................................................................

.67

Magnesia .............................................................................

trace

Water ...................................................................................

5.25

Organic Matter ....................................................................

.32

   
 

100.00

—No. 3 Strong.—

  

Silica...................................

60.32

Alumina ...............................................................................

26.45

Oxide Iron ............................................................................

1.94

Lime .....................................................................................

.63

Magnesia .............................................................................

.55

Alkalis .................................................................................

.08

Water ...................................................................................

11.02

   
 

100.99

—No. 1 Tender.—

  

Silica...................................

64.92

Alumina ..................................................................................

25.53

Ferric Oxide ..........................................................................

2.14

Lime ......................................................................................

.33

Alkalis ...................................................................................

.50

Water and Organic Matter

6.71

 

100.13

—No. 2 Tender.—

  

Silica ...................................................................................

51.11

Alumina ..............................................................................

34.60

Ferric Oxide ........................................................................

3.75

Lime ....................................................................................

.56

Alkalis .................................

.03

Water and Organic Matter ...................................................

9.95

 

100.00

—No. 3 Tender.—

  

Silica ..................................

61.10

Alumina ........................................................................

28.75

Ferric Oxide ...............................................................

1.43

Lime ............................................................................

.27

Alkalis.................................

• • •

Water and Organic Matter ...........................................

8.55

 

100.10

From what is said in regard to them, I judge that the strong clays are considered much better than the tender clays. These analyses are of value for comparison only.

The following may be of considerable interest to many: The Statistics of the Clayworklng Industries of the United States in 1894 contains 139 analyses of fire clays, 25 analyses of kaolins, 37 analyses of pottery clays, 167 analyses of brick clays, 51 analyses of paring brick clays, 8 analyses of terra cotta clays, 8 analyses of pipe clays and 9 analyses of residual clays. Among the fire clays I find eight clays whose chemical analyses would be about the same as the English analysis; among the kaolins one, and one other that could be made up by mixing two clays that occur in the same locality; among the pottery clays none; among the brick clays one; among the paving brick clays none; among the terra cotta clays none; among the pipe clays one, and among the residual clays one; or, out of 444 analyses, there are thirteen clays whose chemical analyses would suit the manufacture of enameled brick according to English methods and rules. Out of these thirteen clays there may be none whose physical properties would be correct. This cannot be predicted from a chemical analysis alone. These clays are divided among the States as follows: Arkansas, 2; New Jersey, 3; North Carolina, 1; North Dakota, 1; Pennsylvania, 2; Texas, 1; Washington, 1; Indiana, 1, and Wisconsin, 1. This leaves out Ohio. I happen to know there are several clays in Ohio eminently fitted for high heat, open burning, and possessing the proper physical properties. There are quite a number of analyses that show a little too much of the alkalis, or too much iron, or too much lime and magnesia, to be worked according to English methods, but if the physical properties are correct, they will yield to American methods whenever the attempt is made to make them yield.