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Full text of "A study of the vitrification range and di-electric behavior of some Porcelains"

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J 



UNIVERSITY OF ILLINOIS BULLETIN 



Vol. VII. MARCH 14, 1910. No. 28 



[Entered February 14, 1902, at Urbana, Illinois, as second-class matter under 
Act of Congress of July 16, 1894. ] 



BULLETIN No. 13 
DEPARTMENT OF CERAMICS 

A. V. BLEININGER, Director 

\ STUDY OF THE VITRIFICATION RANGE 

AND DLELECTRIC BEHAVIOR OF 

SOME PORCELAINS 



BY 

A. V. BLEININGER, Pittsburg, Pa,, and 

R. T. STULL, Urbana, III. 



1909-1910 



PUBLISHED FORTNIGHTLY BY THE UNIVERSITY 



[Reprinted from Transactions of American Ceramic Society, Vol. XII. 
Paper read at Pittsburgh Meeting, February, 1910.] 



A STUDY OF THE VITRIFICATION RANGE AND 

DIELECTRIC BEHAVIOR OF SOME 

PORCELAINS. 

BY 

A. V. Bleininger^ Pittsburg, Pa., and R. T. Stull, 
Urbana, 111. 

The object of this work, Avhich was begun in the sum- 
mer of 1908, was to show by graphical means the propor- 
tions of clay, feldspar and flint which produce vitrified 
clay bodies at temperatures within the limits of American 
practice. At the same time this opportunity was taken 
to show, if possible, the relation between the composition 
of the bodies and their electrical resistance. In order to 
bring out the effect of introducing the various clays used 
in the industries it was decided to cover the field outlined 
by using Tennessee ball clay No. 3, North Carolina kaolin, 
English China clay and Georgia kaolin. All of these 
materials, as well as the feldspar and flint were obtained 
from the Avorks of the Mayer Pottery Company, Beaver 
Falls, Pa., through the kindness of Mr. Ernest Mayer and 
Mr. Her ford Hope. 

The materials were analyzed in tlie chemical depart- 
ment of the University of Illinois. The results of the 
analyses, as well as the empirical formuhTe of tliese compo- 
nents are given in the following table: 

Chemical Analysis of Materials. 



N. C. Kaolin Eng. China Clay Georjia Kaolin. 



Potash Spar. 



BiO 


I 
..! 48.54% 


45.74%o 


47.06% 


46.86%o 


70.03% 


Al,03 ... 


..1 36.25% 


40.18% 


38.70% 


38.67% 


17.80% 


Fe.O., ... 


.07% 


.57% 


.40% 


.57% 


.21% 


CaO .... 


.32% 


.30% 


.58% 


.55% 


.98%, 


MgO .... 


..| .32% 


.34% 


.49% 


.25% 


.16% 


K.O .... 


.70% 


1.19% 


1.05% 


.27% 


8.71% 


Na.,0 .... 


.28% 


.55% 


.23% 


.49% 


1.61% 


H„0 .... 


..1 12.13% 

1 


14.30%c 


12.22% 


13.27% 


.35% 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



Chemical Formulae. 



.0209 K,0 
.0127 Na.O 
Tennessee Ball .0161 Cab 

Clay .. .0225 MgO 

.0722 

' '■ .0321 K.O ^ 
.0225 Na„0 
North Carolina .0136 Cab 
Kaolin 0216 MgO 

.089 8 

r0294"KTxr^ 
.0098 Na.,0 

English China .0273 Cab 

Clay .0323 MgO 



1.0000 ALO.. 
.0118 Fe„0. 2.276 SiO., 



Mol. Wt. = 279.173 



1.0000 ALO, 
.0090 FGoO, 1.935 SiO.. 



Mol. Wt. = 261.898 



1.0000 ALO-i 
.0066 Fe.,b.. 2.067 SiO, 



Mol. Wt. = 265.507 



Georgia Kaolin. 



.0076 K..0 
.0208 Na„0 
.0258 Cab 
.0164 MgO 

.0706 



3.0000 Al.,0, 
.0094 Fe.O.. 2.055 SiO, 



Mol. Wt. = 275.816 



Potash Spar . . 



.5283 K.,0 
.1480 Na.,0 
.0998 Cab 
.0228 MgO 



.7989 



1.0000 Al.,0.. 
.0075 Fe.,0' 6.655 SiO, 



Mol. Wt. --569.832 



The scheme of compounding' the bodies was simple. 
Starting- with a mixture of 50% of clay and 50% of feld- 
spar the latter was gradually replaced by flint down to a 
content of 5% feldspar. The amount of clay was then 
increased to 55% and again the feldspar replaced as be- 
fore. This was continued until a clay content of 80% was 
reached. 

In table I the composition of the bodies and their for- 
mulae are given. 

Preparation of Specimens. 

The clays were blunged and screened in the usual 
manner, and from the prepared bodies two kinds of speci- 
mens were made. For the purpose of obtaining measure- 
ments of the porosity at different temperatures small 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 
TABLE I. 





BATCH 


FORMULA 


No. 


Ga. 
Kaul. 


Spar. 


Flint 


KoO 1 Na^O 


CaO 1 MgO Al,03 FeoOj SiO-. 

i 


A 1 


100 
50 
50 

50 
50 
50 
50 
50 
50 
50 
50 
55 
55 
55 
55 
55 
55 
55 
55 
55 
60 
60 
60 
60 
60 
60 
60 
60 
65 
65 
65 
65 
65 
65 
65 
70 
70 
70 
70 
70 
70 
75 
75 
75 
75 
75 
75 



50 
45 
40 
35 
30 
25 
20 
15 
10 

5 
45 
40 
35 
30 
25 
20 
15 
10 

5 
40 
35 
30 
25 
20 
15 
10 

5 
35 
30 
25 
20 
15 
10 

5 
30 
25 
20 
15 
10 

5 
25 
21 
17 
13 

9 

5 






5 

10 

15 

20 

25 

30 

35 

40 

45 



5 

10 

15 

20 

25 

30 

35 

40 



5 

10 

15 

20 

25 

30 

35 



5 

10 

15 

20 

25 

30 



5 

10 

15 

20 

25 



4 

8 

12 

16 

20 


.0076 


.0208 


.0258 
.0502 
.0485 
.0443 
.0449 
.0427 
.0404 
.0379 
.0352 
.0322 
.0295 
.0476 
.0452 
.0437 
.0416 
.0395 
.0371 
.0346 
.0318 
.0293 
.0438 
.0423 
.0402 
.0383 
.0360 
.0837 
.0311 
.0287 
.0414 
.0396 
.0375 
.0355 
.0332 
.0308 
.0286 
.0392 
.0370 
.0350 
.0329 
.0306 
.0286 
.0361 
.0347 
.0335 
.0310 
.0299 
.0282 


.0164 
.0186 
.0185 
.0184 
.0181 
.0180 
.0180 
.0176 
.0174 
.0171 
.0168 
.0183 
.0182 
.0180 
.0178 
.0177 
.0175 
.0173 
.0170 
.0168 
.0181 
.0179 
.0177 
.0177 
.0174 
.0172 
.0170 
.0168 
.0178 
.0174 
.0175 
.0173 
.0172 
.0170 
.0168 
.0176 
.0175 
.0173 
.0172 
.0170 
.0168 
.0174 
.0170 
.0172 
.0166 
.0170 
.0168 


1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 


1 

.0095 
.0089 
.0088 
.0091 
.0091 


2.055 


2 


.1777 
.1660 
.1531 
.1397 
.1248 
.1093 
.0925 
.0742 
.0534 
.0316 
.1555 
.1430 
.1303 
.1163 
.1015 
.0857 
.0682 
.0498 
.0293 
.1349 
.1226 
.1088 
.0953 
.0804 
.0640 
.0468 
.0279 
.1154 
.1027 
.0893 
.0754 
.0599 
.0438 
.0262 
.0973 
.0847 
.0717 
.0568 
.0417 
.0252 
.0801 
.0700 
.0593 
.0472 
.0362 
.0239 


.0625 
.0596 
.0565 
.0535 
.0496 
.0458 
.0416 
.0323 
.0322 
.0268 
.0571 
.0541 
.0598 
.0476 
.0440 
.0401 
.0359 
.0314 
.0264 
.0502 
.0440 
.0457 
.0425 
.0388 
.0349 
.0307 
.0261 
.0471 
.0441 
.0408 
.0373 
.0336 
.0296 
.0254 
.0427 
.0397 
.0364 
.0329 
.0291 
.0252 
.0380 
.0363 
.0335 
.0303 
.0278 
.0285 


3.555 


3 


3.675 


4 


4.002 




4.249 


6 


.009014.513 


7 


.009414.850 


8 


.0093 5.113 


9 


.0092 5.450 


10 


.0091|5.817 


11 


.00954.216 


12 


.009013.359 


13 


.0093 3.557 


14 


.0092 3.775 


15 


.00914.008 


16 


.0095 4.254 


17 


.0094 4.520 


18 


.0093 4.807 


19 


.0092 5.114 


20 


.0096 5.456 


21 


.0090|3.178 


22 


.0089|3.367 


23 


.008913.556 


24 


.0091 
.0091 
.0090 
.0089 
.0093 
.0091 
.0090 
.0093 


3.781 


25 


4.015 


26 


4.262 


27 


4.527 


28 


4.813 


29 


3.006 


30 


3.187 


31 


3.368 


32 


. 009213. 571 


33 


.0092 3.790 


34 


.00914.021 


35 


.0094 


4.266 


36 


.0091 
.0094 
.0093 
.0094 
.0092 
.0095 
.0092 
.0092 
.0090 
.0090 
.0090 
.0093 


2.846 


37 


3.013 


38 


3.192 


39 


3.381 


40 


3.582 


41 


3.796 


42 


2.692 


43 


2.788 


44 


2.625 


45 

46 

47 


3.028 
3.236 

3.387 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 

TABLE I — Continued. 





BATCH 


FORUMLA 


No 


Ga. 

Kaol. 


Spar 


Flint 


K,0 


Na^O 


CaO 


MgO 


AI2O3 


Fe^Oa 


SiOo 


A 48 


75 

80 
80 
80 
80 
80 
80 
80 

Tenn. 
Ba'l. 

100 
50 
50 

50 
50 
50 
50 
50 
50 
50 
50 
55 
55 
55 
55 
55 
55 
55 
55 
55 
60 
60 
60 
60 
60 
60 
60 
60 
65 
65 
65 
65 
65 
65 
65 
70 
70 
70 
70 
70 


1 

20 
17 
14 
11 

8 
5 
2 


50 
45 
40 
35 
30 
25 
20 
15 
10 

5 
45 
40 
35 
30 
25 
20 
15 
10 

5 
40 
35 
30 
25 
20 
15 
10 

5 
35 
30 
25 
20 
15 
10 

5 
30 
25 
20 
15 
10 


24 



3 

6 

9 

12 

15 

18 





5 

10 

15 

20 

25 

30 

35 

40 

45 



5 

10 

15 

20 

25 

30 

35 

40 



5 

10 

15 

20 

25 

30 

35 



5 

10 

15 

20 

25 

30 



5 

10 

15 

20 


.0109 

.0640 
.0563 
.0483 
.0401 
.0314 
.0228 
.0140 

.0209 
.1876 
.1764 
.1636 
.1502 
.1359 
.1206 
.1041 
.0857 
.0661 
.0442 
.1663 
.1542 
.1416 
.1276 
.1133 
.0980 
.0806 
.0599 


.0218 
.0346 
.0328 
.0308 
.0291 
.0270 
.0250 
.0225 

.0127 
.0573 
.0543 
.0509 
.0472 
.0436 
.0395 
.0350 
.0302 
.0250 
.0192 
.0515 
.0483 
.0449 
.0401 
.0374 
.0332 


.0282 
.0339 

.0328 
.0318 
.0304 
.0293 
.0281 
.0268 

.0161 
.0438 
.0415 
.0393 

. 0378 


.0163 
.0173 

.0172 
.0172 
.0168 
.0168 
.0167 
.0167 

.0225 
.0225 
.0225 
.0224 
.0224 


1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 

1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 


.0092 
.0092 


3.549 


49 


2.552 


50 


.009012.639 


51 


.0092 
.0091 
.0092 


2 733 


52 


2.829 


53 


'). c»57 


, 54 


.0094 3.278 


55 


.0092 3 134 


B 1 


.0118 2.27fi 


2 


.0105 
.0105 
.0108 
.0108 
.0108 
.0112 


3.715 


3 


3.937 


4 


4.177 


5 


4.432 


6 


.0354 .0224 
.0327 .0224 
.0300 .0224 


4.707 




5 . 000 


8 


.0112i5.327 


9 


.0268 
.0234 
.0202 
.0402 
.0382 
.0364 
.0340 
.0311 
.0289 


.0224 
.0224 
.0223 
.0224 
.0224 
.0225 
.0224 
.0224 
.0224 
.0224 
.0214 
.0223 
.0224 
.0224 
.0224 
.0225 
.0224 
.0224 
. 0223 
.0223 
.0224 
.0224 
.0224 
.0224 
.0224 


.0112i5.677 


10 


.011216.058 


11 


.011716.471 


12 


.010513.528 


13 


.01093.738 


14 


.010813.951 


15 


.01084.195 


16 


.0112 4.455 


17 


.0112 4.735 


18 • 


.0287 .0260 


.0112 5.027 


19 


.0227 


.0218 
.0200 
.0368 
.0351 
.0329 
.0305 
.0280 
.0253 
.0223 
.0197 
.0340 
.0319 
.0297 
.0272 
.0247 


.0107 5.111 


20 


. 04241. OlS.'j 


.011615.700 


21 


.1459 
.1339 
.1207 
.1070 
.0924 
.0763 
.0509 
.0407 
.1271 
.1145 
.1016 
.0877 
.0726 
.0568 
.0393 
.1088 
.0964 


.0463 
.0435 
.0400 
.0359 
.0320 
.0279 
.0232 
.0183 
.0411 
.0378 
.0343 
.0306 
.0266 
.0224 
.0178 
.0363 
.0329 


.0109 3.354 


22 


.0109 3.550 


23 

24 

25 

26 

27 

28 

29, 

30 

31 


.0108 3.760 
.0112 3.984 
.011214.224 
.0112 4.482 
.0112 4.758 
.011615.059 
.010913.189 
.010913.725 
.OII2I3.494 


32 


.011213.781 


33 


.011214.001 


34 


.0220 .0224 
.0194 .0224 
.0310 .0224 
.02821.0224 
.0266 .0224 
.0245 .0224 
.0216 .0224 


.011214.245 


35 


.011614.504 


36 


.011013.035 


37 


.011113.244 


38 


.0833 .0294 
.0689 .0257 
.0541 .0216 


1 . 000 


.011213.398 


39 


1.000 
1.000 


.011213.595 


40 


.011213.805 



















VITRIFICATION RANGE AND DI-ELECTRIC BKHAVIOR. 



TABLE I— Continued. 



i 


BATCH 




FORUMLA 


., Tenn. 
N°- Ball, j 


Spu 


Flint 


K.O Na..O CaO MgO 


AI2O., 


FeoOa 


SiOo 


B 41 


70 

75 
75 
75 
75 
75 
75 
75 
SO 
80 
80 
80 
80 
80 
80 

N. C. 
Kail. 
100 

50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
55 
55 
55 
55 
55 
55 
55 
55 
55 
60 
60 
60 
60 
60 
60 
60 
60 
65 
65 
65 
65 
65 


5 

25 

21 

17 

13 

9 

5 

1 

20 

17 

14 

11 

S 

5 

2 


50 
45 
40 
35 
30 
25 
20 
15 
10 

5 
45 
40 
35 
30 
25 
20 
15 
10 

5 
40 
35 
30 
25 
20 
15 
10 

5 
35 
30 
25 
20 
15 


25 1 



4 ' 

8 
12 
16 
20 
24 



3 

6 

9 
12 
15 
18 





5 
10 
15 
20 
25 
30 
35 
40 
45 



5 
10 
15 
20 
25 
30 
35 
40 



5 
10 
15 
20 
25 
30 
35 



5 
10 
15 
20 


.0339 .0173i 0193|- >^'>.9.4.\ 


1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1 . 000 


0I15U 030 


42 


.0922 0.^171 (i'>S9 


.0224J 
.0223 
.0224 
.02231 
.0223; 
.0223: 
.02221 


0ll2i2 891 


43 

44 


.0822 
.0717 


.0291 .0265 
.0261 .0248 


.01113.022 
0111 3 159 


45 


.0607 
.0488 
.0368 
.0241 
.0765 
.0689 
.0611 
.0530 
.0446 
.0359 
.0238 

.0321 
.1884 
.1774 
.1654 
.1530 
.1392 
.1248 
.1093 
.0921 
.0739 
.0535 
.1678 
.1207 
.1444 
.1313 
.1177 
.1033 
.0872 
.0703 
.0517 
.1483 
.1372 
.1245 
.1117 
.0980 
.0830 
.0673 
.0500 
.1303 
.1153 
.1065 
.0935 
.0794 


.02341.0230 
.02021.0212 
.0170|.0191 
.013'/|.0170 


01133 305 


46 


.011213.457 
.0115 3.619 


47 


48 


.0115 3-787 


49 


.O277I.O252 


09'2r 


.0115 
.0114 
.0115 
.0115 


2.753 


50 


.0256 .0240J. 0224 
. 02351. 0228i. 0225 


2.846 


51 


2.942 


52 


.02161. 02131.022211. 000 
.01931.0200 .0223 1.000 
. 01691. 0j86 .0223 1.000 
.0145|.0173 .0224il.000 


3 . 041 


53 


.0116 3.151 


54 


.0118 
.0117 

.0090 

.0086 
.0085 
.0088 
.0087 
.0087 
.0085 
.0089 
.0088 
.0087 
.0090 
.0086 
.0089 
.0088 
.0087 
.0090 
.0090 
.0089 
.0089 
.0090 
.0087 
.0086 
.0085 
.0088 
.0087 
.0086 
.0085 
.0088 
.0087 
.0086 
.0089 
.0089 
.0087 


3.251 


55 


3.456 


G 1 


.0225 


.0136 


.0216 


1.000 


1.935 


2 


.0621 
.0593 
.0563 
.0531 
.0496 
.0460 
.0420 
.0378 
.0331 
.0280 
.0567 
.0539 
.0508 
.0476 
.0441 
.0400 
.0364 
.0321 
.0274 
.0520 
.0493 
.0461 
.0432 
.0394 
.0356 
.0316 
.0273 
.0471 
.0446 
.0414 
.0381 
.0346 


.0409 
.0352 
.0364 
.0349 


.0219 
.0219 
.0218 
.0218 


1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 


3.420 


3 


3.623 


4 


3.842 


5 


4.073 


6 


.0324 


.0218 


4.323 


7 


.0298 
.0270 
.0239 
.0206 
.0175 
.0374 
.0354 
.0335 
.0312 
.0287 


.0217 
.0217 
.0217 
.0216 
.0215 
.0218 
.0218 
.0217 
.0217 
.0216 


4.591 


8 


4.880 


9 


5.192 


10 


5.532 


11 


5.898 


12 


3.224 


13 


3.417 


14 


3.616 


15 


3.832 


16 


4.061 


17 


.02611.0216 


4.312 


18 


.0233 
.0202 
.0174 
.0337 
.0321 


.0216 
.0215 
.0215 
.0217 
.0217 


4.577 


19 


4.863 


20 


5.171 


21 


3.037 


22 


3.225 


23 


.02981.0216 
.02751.0216 
.0250L0216 
.0223i.0215 


3.404 


24 


3.609 


25 


3.823 


26 


4.053 


27 

28 


.0195 
.0168 
.0310 


.0215 
.0215 
.0216 


4.299 
4.559 


29 


2.867 


30 


.02891.0216 
.02671.0216 
.02441.0216 


3.036 


31 


3.214 


32 


3.401 


33 


.0219 


|.0215 


13.601 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



TABLE 1 — Continued. 



BATCH 


FORUM LA 


No. 


N. C. 
Kaol. 


Spar 


Flint 


KjO 


NaoO 


CaO MgO 


Al.,03 FeoOs 


biOo 


34 


65 

65 

70 
70 
70 
70 
70 
70 
75 
75 
75 
75 
75 
75 
75 
80 
80 
80 
80 
80 
80 
80 

E"g. 
Cliiim 

100 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
55 
55 
55 
55 
55 
55 
55 
55 
55 
60 
60 
60 
60 
60 
60 


10 

5 

30 

25 

20 

15 

10 

5 

25 

21 

17 

13 

9 

5 

1 

20 

17 

14 

11 

8 

5 

2 


50 
45 
40 
35 
30 
25 
20 
15 
10 

5 
45 
40 
35 
30 
25 
20 
15 
10 

5 
40 
35 
30 
25 
20 
15 


25 

30 



5 

10 

15 

20 

25 



4 

8 

12 

16 

20 

24 



3 

6 

9 

12 

15 

18 





5 

10 

15 

20 

25 

30 

35 

40 

45 



5 

10 

15 

20 

25 

30 

35 

40 



5 

10 

15 

20 

25 


1 

.0647 
.0486 
.1145 
.1019 
.0899 
.0763 
.0624 
.0474 


.0309 
.0268 
.0431 
.0401 
.0370 
.0337 
.0302 
.0264 


.0192 .0214 


1.000 
1.000 

1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 


! 
.0086 
.0089 
.0088 
.0090 
.0089 
.0089 
.0088 


3.815 


35 


.0167 


.0214 


4.045 


36 


.0247 
.0257 
.0235 
.0211 
.0186 
.0163 
.0254 
.0235 
.0219 
.0201 
.0182 
.0163 
.0142 
.0226 
.0215 
.0203 
.0188 
.0175 
.0162 
.0149 

.0273 
.0504 
.0487 
.0468 
.0332 
.0431 
.0409 
.0385 
.0360 
.0330 
.0304 
.0475 
.0458 
.0443 
.0423 
.0402 
.0380 
.0356 
.0330 
.0306 
.0446 
.0431 
.0405 
.0382 
.0371 
.0349 


.0218 
.0215 
.0215 
.0215 
.0214 
.0214 
.0216 
.0214 
.0215 
.0214 
.0215 
.0214 
.0212 
.0217 
.0218 
.0218 
.0216 


2.680 


37 


2.892 


38 


3.067 


39 


3.243 


40 


3.428 


41 


.0090 3.632 


42 


.0979 


.0391 


.0090 2.231 


43 


.0885 
.0788 
.0686 
.0576 
.0464 
.0347 
.0835 
.0763 
.0691 
.0616 
.0538 
.0459 
.0379 

.0294 
.1880 
.1770 
.1648 
.1480 
.1382 
.1236 
.1079 
.0904 
.0718 
.0513 
.1675 
.1558 
.1437 
.1304 
.1168 
.1020 
.0857 
.0686 
.0495 
.1475 
.1360 
.1235 
.1104 
.0965 
.0812 


.0369 
.0342 
.0317 
.0288 
.0261 
.0233 
.0355 
.0337 
.0318 
.0302 
.0281 
.0261 
.0239 

.0098 
.0536 
.0505 
.0472 
.0436 
.0398 
.0358 
.0313 
.0266 
.0214 
.0157 
.0480 
.0447 
.0413 
.0377 
.0338 
.0297 
.0253 
.0204 
.0153 
.0425 
.0393 
.0359 
.0322 
.0283 
.0242 


.0090 2.681 


44 


.0090 
.0090 
.0090 
.0090 
.0090 
.0089 


2.802 


45 


2.932 


46 


2.066 


47 


3.206 


48 


3.353 


49ft 


2.451 


50 


.008712.504 


51 


.008812.588 


52 


.0086 2.678 


53 


.0216 1.000 


.0087 2.764 


54 


.0217 
.0217 

.0323 
.0293 
.0296 
.0298 
.0300 
.0303 
.0306 
.0309 
.0312 
.0315 
.0320 
.0297 
.0299 
.0302 
.0303 
.0306 
.0314 
.0317 
.0316 
.0320 
.0300 
.0303 
.0313 
.0308 
.0310 
.0305 


1.000 
1.000 

1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 


.0089 2.863 


55 


.0090 2.959 


D 1 


.0066 2.067 


2 


.0069 3.525 


3 


.006713.734 


4 


.006913.957 


Q 


.0068 


4.192 


6 


.0066 
.0069 
.0067 
.0066 
.0064 


4.452 




4.728 


s 


5.003 


9 


5.348 


10 


5.698 


11 


l.OOOl. 006616. 077 


12 


1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 


.007013.334 


13 


.007213.529 


14 


.0071 
.0069 
.0072 
.0070 


3 . 692 


15 


3.956 


16 


4.197 


17 


4.453 


18 


.0069 4.729 


19 


.0067 5.023 


20 


.00715.340 


21 


.007113.150 


22 


.007013.336 


23 


.0068 
.0070 
.0069 
.0067 


3.531 


24 


3.738 


25 


3.961 


26 


4.197 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



TABLE I— Continued. 



j 


BATCH 








I 


^ORUMLA 






No. 1 


ling. 
China 


Spar 


Flint 


K3O NaoO CaO 


MgO 


AI2O3 


Fe^O^ SiOo 


D 27 


60 

60 
65 
65 
65 
65 
65 
65 
65 
70 
70 
70 
70 
70 
70 
75 
75 
75 
75 
75 
75 
75 
80 
80 
80 
80 
80 
80 
80 


10 

5 

35 

30 

25 

20 

15 

10 

5 

30 

25 

20 

15 

10 

5 

25 

21 

17 

13 

9 

5 

1 

20 

17 

14 

11 

8 

5 

2 


30 

35 



5 

10 

15 

20 

25 

30 



5 

10 

15 

20 

25 



4 

8 

12 

16 

20 

24 



3 

6 

9 

12 

15 

18 


.0653 .0197 
.0477 .0149 
.1296 .0375 
.1176 .0343 
.1053 .0308 
.0921 .0271 
.0778 -0232 


.0324 
.0302 
.0421 
.0403 
.0384 
.0364 
.0343 
.0320 
.0300 
.0395 
.0377 
.0358 
.0338 
.0316 
.0297 
.0371 


.0316 

.0319 
.0304 
.0306 
.0308 
.0311 
.0309 
.0316 
.0319 
.0307 
.0309 
.0311 
.0314 
.0316 
.0319 
.0309 
.0310 
.0313 
.0314 
.0320 


1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 


.0065 4 451 


28 


.0068 
.0069 
.0067 
.0069 
.0068 


4.719 


29 


2.987 


30 


3.159 


31 


3 . 342 


32 


3 . 5.34 


33 


.0066 3.74fi 


34 


.0629 
.0465 
.1122 
.1005 
.0881 
.0745 
.0605 


.0190 
.0146 
.0326 
.0296 
.0261 
.0224 
.0185 


.0065 
.0067 
.0067 
.0068 
.0069 
.0065 
.0064 
.0066 
.0071 
.0068 
.0067 
.0069 
.0069 


3.963 


35 


4.198 


36 


2.831 


37 


2.993 


38 


3.169 


39 


3.345 


40 


3.554 


41 


.04511.0143 


3.745 


42 


.0971 
.0868 
.0771 
.0668 
.0557 
.0443 
.0323 
.0814 
.0743 
.0669 
.0594 
.0514 
.0432 
.0351 


.0285 


2.684 


43 


.0260|.0338 
.02311.0342 
.0203 .0321 
.0176 .0315 
.01441.0295 


2.800 


44 


2.932 


45 


3.062 


46 


3.205 


47 


.0319il.000 
.032011.000 


.006913.350 


48 


.0109 
.0244 
.0223 
.0203 
.0181 
.0162 
.0142 
.0114 


.0279 
.0348 
.0338 
.0328 
.0316 
.0304 
.0294 
.0282 


.0067 
.0068 
.0066 
.0068 
.0069 
.0066 
.0068 
.0066 


3 . 503 


49 


.0315 
.0320 
.0319 
.0319 
.0320 
.0322 
.0321 


1.000 
1.000 
1.000 
1.000 
1.000 
1.000 
1.000 


2.546 


50 


2.631 


51 


2.718 


52 


2.812 


53 


2.906 


54 


3.005 


55 . . . . 


3.150 







brickettes were molded, weighing from 25 to 30 grams iii 
the burnt condition. For obtaining the electrical resist- 
ance small dishes of the shape shown in Fig. 1 were jig- 
gered. These dishes had a diameter of about 3 3/16 inch, 
and a depth of V4 inch in the burnt state. All of the test 
pieces were burnt in saggers in a coal fired down-draft 
kiln, and special attention was paid to the observation of 
the temperatures by distributing cones throughout the 
kiln. The length of burning varied from 36 to more than 
48 hours. 

After burning, the porosity of the brickettes was de- 
termined in the manner repeatedly described in the Trans- 



8 VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 

actioiis of this society. In addition, the speeilic gravity of 
the pulverized brickettes was determined by means of the 
pyciiometer. After grinding the porcelain specimens in 
the jaw crusher and in iron mortars, pains were talvcn to 
remove the metallic particles by means of a magnet. The 
true specific gravity of the bodies was determined primar- 
ily for the pui'i^ose of obtaining the volume of the enclosed 
pore space, for which it was hoped to establish some rela- 
tion as regards temperature and content of feldspar. 

The specimens for the electrical tests ^^ere selected 
by inspection from the burns, Avhich resulted in apparently 
vitrified bodies. The puncture tests were conducted in the 
Electrical Laboratoiy of the University of Tllinois, under 
the direction of Mr. Thomas H. Amrine. The arrangement 
of the specimen for the test is shown in Fig. 1. The read- 
ings of the voltmeter below 10,000 volts were not as 
accurate as was desired, and it would have been better if 
the thickness had been greater, as the instrument was de- 
signed for readings above 10,000 volts. 

The results of this work expressed in graphical form, 
ill which they tell their own story, are discussed under 
the following headings : 

1. Composition areas showing the mixtures resulting 
in vitrified bodies at several temperatures. All bodies 
alisorbing not more than 0.1% of water, by weight, upon 
boiling in vacuo are considered vitrified. The compositions 
are plotted by means of triaxial diagrams and are ex- 
pressed in simple percentages of clay, feldspar and flint. 

2. Composition areas plotted in a rectangular co- 
ordinate system, the abscissae representing molecular 
equivalents of the EO constituents and the ordinates mole- 
cules of silica. 

This system is used simply as a means of classification 
for the purpose of outlining the general effect of chemical 
composition. The writers fully recognize the fact that we 
are here not dealing with homogeneous igneous compounds 
and solutions, owing to the fact that the materials are not 



VITRIFICATIOX RANGE AND Dl-EL.ECTRIC BEHAVIOR. i) 

reduced to maximum fineness and that the viscosity is still 
so great that no appreciable deformation of the burnt 
specimens is observable at the temperatures employed. 
Ho\\ ever, the fact remains that these mixtures ai-e blended 
sufficiently intimate and soften enough to bring about 
jnolecular interaction which, though far from having 
reached equilibrium conditions, still justifies the use of 
chemical nomenclature. It might be suggested that the 
mineral composition be used as the basis of comparison, 
but this likewise is open to the objection that we must 
assume the presence of clay and feldspar corresponding to 
theoretical formulre. From the standpoint of fact there 
should be no objection to the use of tlie empirical formula 
based as it is upon knowledge of a positive kind, the re- 
sults of the chemical analysis. The l)0undar3^ curves in the 
nature of the case are fixed by the burning conditions 
which prevailed in carrying out these tests. Longer burn- 
ing would tend to lower the vitrification temperature, 
shorter burning would raise it. 

3. In this group the apparent porosity at cone 9-10 
is correlated with the feldspar-fiint content for 50 and 
60 9f of clay. 

4. Tlie (liagranis of lliis group illustrate the decrease 
in porosity with increasing temperatures, i. e., they ex- 
press the progress of viti-ification. These data are pre- 
sented for varying fehls]tai'-fiint contents for both 50 and 
00% of clay. 

5. In these diagrams the decrease in true specific 
gravity with increasing temperatures is shown for various 
proportions of feldspar and Hint. The data of two series 
with 50 and C>0^( of clay are presented. In previotis work 
the fact that the true specific gravity of silicates decreases 
as fusion progresses has been sufficiently brought out and 
is here again illustrated. It might be said in this respect 
that the determination of the true specific gravity was 
decided upon principally for the purpose of calculating 
the volume of the enclosed pore space, the "bleb" structure 



10 



VITRIFICATION RANGE AND DI-ELECTRJC BEHAVIOR. 



of Purdy, but on plotting the curves it was found that 
these relations were exceedingly irregular. It was shown 
roughly that the enclosed pore space increased with the 
feldspar content but it also appeared that the initial struc- 
ture of the body, the varying degree of density attained in 
molding, the amount of water employed, etc., is an im- 
portant factor in this respect, which precluded the possi- 
bility of showing any simple correlation. 

6, In this group the composition of the bodies is 
again presented by means of triaxial diagrams, and the di- 
electric strength shown by the jiggered vitrified test pieces 



TRANi AM. CER.SOC VOUIl 



BLEININQER ):5TULL. 




is indicated b3^ areas representing voltages per mm. of less 
than 10,000 volts, of 10000-14000 volts and of from 14000- 
18000 volts. Table II shows the voltages for the various 
mixtures at several burning temperatures. 



VITRIFICATION RANGE AND UI-EIjECTRIC BEHAVIOR. 
TABLE II. 



11 







Total Punc. 


Thickness 


Punc. Ya in. 


Punc. 


No. 




Voltage 


mm. 


Volts 


Volts per mm. 


A 1 


12+ 


45,820 


3.15 


46,188 


14,546 




13 


26,680 


3.13 


27,080 


8,581 


2 


61/2 


37,480 


2.52 


47,225 


14,873 




9 


34,400 


2.70 


40,454 


12,741 




12+ 


35,100 


2.83 


39,382 


12,403 


3 


9 


32,600 


2.62 


39,316 


12,400 




12+ 


37,000 


2.70 


43,512 


13,700 




13 


27,000 


2.64 


32,454 


10,227 


4 


9 


38,600 


2.95 


41,534 


13,085 




12+ 


53,970 


2.97 


57,640 


18,172 




13 


30,640 


2.66 


36,584 


11,520 


5 


10 


40,700 


3.08 


41,962 


13,214 




13 


37,800 


2.48 


48,422 


15,322 




12+ 


55,040 


3.13 


55,866 


17,585 




13 


34,780 


2.74 


40,310 


12,700 


6 


12+ 


36,240 


2.79 


41,314 


12,989 




13 


41,100 


2.96 


44,059 


13,885 


7 


12 + 

13 

12 


47,960 


2.94 


51,749 


16,313 


8 


33,500 


3!06 


34,V73 


i6,944 




12+ 


33,500 


3.13 


34,003 


10,703 




13 


28,500 


3.08 


29,384 


9,285 


9 


12 V2 

13 

13 


35,860 


3.03 


37,545 


11,835 


10" 




• • • • 






11 


121/2 












13 


38,'606 


3!oi 


46,685 


i2,V24 


12 


61/2 


49,620 


2.72 


57,956 


18,242 




10 


45,610 


2.92 


49,578 


15,620 




12+ 


31,490 


3.00 


33,317 


10,496 


13 


12 + 


38,980 


3.06 


40,461 


12,738 




13 


43,400 


3.02 


45,570 


14,371 


14 


12 + 


39,170 


3.03 


41,011 


12,927 


15 


12+ 


40,120 


2.94 


43,290 


13,646 




13 


39,360 


2.98 


41,918 


13,208 


16 


12+ 


43,580 


3.07 


45,236 


14,195 




13 


38,120 


3.24 


37,358 


11,765 


17 


12 


32,600 


2.70 


38,338 


12,074 




12+ 


38,280 1 


2.95 


41,189 


12,976 




121/2 


47,780 


2.79 


54,469 


17,125 




13 


27,750 1 


2.93 


30,053 


9,471 


18 


12 


23,700 


3.06 


24,601 


7,745 




121/2 

13 
12 


23,700 1 


3.10 


24,269 


7,645 


19 


i 








i 


13 










20 


12 

121/2 











12 



VITRIFICATION RANGE AND DI-ELECTRIC I'.EHAVIOR. 



TABLE II— Continued. 







Total Punc 


Thickness 


Punc. !4 in. 


Pjnc. 


No. 


Cone 


Voltage 


mm. 


Volts 


Volts per mm. 


A 21 


12 + 


43,660 


2.82 


49,161 


15,482 




121/2 


38,980 - 


2.80 


44,142 


13,914 




13 


40,500 


2.70 


47.628 


15,000 


22 


6 


40,500 


2.91 


44,185 


13,917 




12+ 


41,100 


2.76 


47.306 


14,891 




13 


32,750 


2.74 


37,976 


11,952 


23 


12+ 


41,100 1 


2.76 


47,306 1 


14,891 




13 


37,000 


2.85 


41,218 


12,982 


24 


12 + 


44,300 


2.89 


48,641 


15,328 




13 


40,100 


2.93 


43,328 


13,686 


25 


12+ 


35,660 


2.91 


38,905 


12,254 




13 


44,490 


2.70 


52,320 


16,477 


20 


13 




• • • • 






27 


13 










28 


13 










29 


12+ 


3 7, 8 00 


2 '.66 


45.133 


14,210 




121/2 


41,700 


2.60 


50,916 


16,038 




13 


33,500 


2.62 


40,568 


12,786 


30 


12 + 


35,100 


2.92 


38,154 


12,020 




121/2 


44,680 


2.77 


51,248 


16,130 




13 


43,940 . 


2.87 


48,598 


15,310 


31 


13 


42,860 


2.91 


46,760 


14,732 


32 


121/, 


38,280 


2.94 


41,304 


13,020 




13 


38,280 , 


2.80 


43,448 


13,671 


33 


121/2 


31,320 


2.88 


34,515 


10,867 




13 


26,840 


2.76 


30,893 


9,'f24 


34 


121/, 
13 


'.'.'.'.'.'. 








35 


13 










36 


11 


39,360 


2.84 


44,004 


iiVsg 




121/2 


41,700 


2.83 


46,787 


14,731 


37 


6 


26,040 


2.57 


32,160 


10,132 




11 


43,580 


2.82 


49,071 


15,453 




13 


33,050 


2.78 


37,810 


11,888 


38 


11 


26,840 


2.96 


28,772 


9,067 




12 


23.700 


2.81 


26,781 


8,434 




13 


39,360 


2.97 


42,036 


13,253 


39 


12 


23,700 


2.54 


29,625 


9,330 




121/2 


23,700 


2.87 


26,212 


8,257 




13 


33,050 


2.73 


38,470 


12,106 






34,140 


2.81 


38,578 


12,146 


40 


12 

121/2 

13 











41 


12 

121/2 

13 


25,060 



3!73 


21,351 




* 6,Vl8 


42 


11 


29,660 


3.17 


2 9, '7 19 


'9,356 




121/2 


34,140 


3.21 


33,764 


10,636 




13 


39,740 


3.07 


/I '"-! 


l?.9ir, 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



13 



TABLE II— Continued. 



No. 


Cone 


Tot.lPuuc. 
Voltage 


Tbicki.es3 
mm. 


1 Punc. V& in. 
: \'olts 


Punc. 
Volts per mm. 


A 43 


11 


32,600 


3.27 


30,655 


9,970 




12 


45,060 


3.08 


46,467 


14,630 




13 


29,940 


3.18 


29,937 


9,415 


44 


12 


30,980 


3.26 


30,175 


9,503 




121/2 


38,280 


3.36 


36,175 


11,393 




13 


23,700 


3.23 


23,297 


7,338 


45 


6 


30,300 


3.30 


' 29,149 


9,182 




12 


25,400 


3.32 


24,282 


7,651 




121/2 












13 


22,'680 


3.37 


2i,*.565 


' h'j'i'o 


46 


121/2 


25,400 


3.47 


23,241 


7,323 


47 


121/2 

13 

13 


23,700 


3.46 


21,757 


6,850 


48 










49 


13 


37,960 


3.10 


38,871 


i2,'245 


50 


13 


36,240 


3.31 


34,754 


10,948 


51 


13 


39,740 


3.06 


41,250 


12,987 


52 


IS 


29,220 


3.15 


29,453 


9,276 


53 


13 


26,200 


3.24 


25,676 


8,086 


54 


13 


26,040 


3.36 


24,607 


7,750 


55 


13 


23,700 


3.42 


21,993 


6,930 


B 1 


10% 


34,620 


2.77 


39,659 


12,498 




11 


33,500 


3.08 


34,539 


10,876 




12 


36,430 


2.83 


40,874 


12,873 




121/2 


32,300 


2.60 


39,438 


12,423 


2 


6Vz 


48,300 


3.30 


46,469 


14,636 




10 


45,250 


3.26 


44,074 


13,880 




10 y2 


46,010 


3.21 


45,504 


14,333 


3 


evz 


42,300 


3.20 


41,962 


13,220 




10 


43,760' 


3.33 


41,894 


13,141 




101/0 


51,700 


3.24 


50,666 


15,957 


4 


6 1/2 


48,520 


3.27 


45,113 


14,838 




81/2 


48,960 


3.31 


46,953 


14,770 




101/2 


50,280 


3.55 


44,950 


14,163 


5 


814 


49,400 


3.25 


48,264 


15,200 




11 


48,960 


3.28 


47,393 


14,927 




1214 


42,300 


3.32 


40,439 


12,741 


6 


8V0 


43,400 


3.30 


41,751 


13,152 




11 


43,220 


3.19 


43,080 


13,548 




1214 


47,460 


3.40 


44,328 


13,960 


7 


81^ 


38,980 


3.12 


39,682 


12,494 




11 


41,900 


3.02 


43,995 


13,874 




1214 


39,170 1 


3.09 


40,228 


12.676 


8 


10 


35,670 1 


3.23 


35,064 


11,043 




12+ 


28,860 


3.30 


27,763 


8,745 




121/4 


48,740 


3.12 


49,617 


15,622 


9 


12 


36,430 


3.12 


37,086 


11,676 




12+ 


48,300 1 


3.20 


47,914 


15,094 


10 


12 


33,200 1 
1 


3.54 


29,780 


9,380 



14 VITRIFICATION RANGE AND DI-EfiECJTRIC BEHAVIOR. 

TABLE II— Continued. 







Total Punc. 


Thickness 


Punc. /^ in. 


Pane. 


No. 


Cone 


Voltage 


mm. 


Volts 


Volts per mm. 


B 11 


12 


1 

24,720 i 


3.60 


21,793 


6,866 


12 


61/2 


40,500 


3.21 


40.055 


12,617 




8 1/2 


40,700 


3.23 


40,008 


12,600 




12% 


30,470 


3.34 


28,977 


9,123 


13 


6V^ 


44,300 


3.21 


43,713 


13,800 




8y2 


39,930 


2.95 


41,965 


13,535 




12+ 


25,720 


3.46 


23,611 


7,404 


14 


61/2 


38,600 


3.31 


37,017 


11,360 




9 


29,580 


3.17 


29,639 


9,331 




10 


31,830 


3.26 


31,002 


9,764 




12+ 


32,750 


3.36 


30,949 


9,747 


15 


61/2 


41,700 


3.33 


39,740 


12,523 




10 


45,530 


3.26 


44,346 


13,963 




12 


38,280 


3.54 


34,337 


10,814 


16 


61/2 


47,460 


3.26 


46,226 


14,558 




81/2 


58,830 


3.22 


58,006 


18,276 




12 


54,180 


3.32 


51,796 


16,320 


17 


81.^ 


40,310 


3.46 


37,005 


11,650 




10 


33,660 


3.25 


32,886 


10,357 




12 


49,350 


3.09 


50,682 


15,971 




12+ 


49,180 


3.12 


50,065 


15,763 


18 


12 


53,920 


3.18 


53,870 


16,956 




12% 


53,340 


3.02 


56,007 


17,662 


19 


12 


36,050 


3.09 


37,023 


11,666 




121/4 


33,980 


3.05 


35,373 


11,141 


20 


12 


39,360 


3.47 


36,015 


11,343 




121/4 


29,760 


3.24 


29,155 


9,186 




121/2 


41,300 


3.35 


39,152 


12,330 


21 


6V2 


45,630 


3.19 


45,448 


14,304 




9 


44,490 


3.17 


44,579 


14,035 




12 + 


34,140 


3.26 


1 33,252 


10,472 


22 


6 1/2 


47,620 


3.11 


48,621 


15,312 




9 


44,870 


3.02 


1 47,114 


14,858 




12+ 


42,860 


3.08 


1 44,189 


13,915 


23 


8 1/2 


38,600 


3.06 


1 40,067 


12,614 




12+ 


44,680 


3.15 


i 45,037 


14,184 




i2y2 


36,620 


1 2.59 


j 44,860 


14,140 




13 


42,100 


2.98 


1 44,839 


14,127 


24 


8% 


51,100 


3.06 


1 53,042 


16,700 




12+ 


40,900 


1 3.04 


1 42,700 


14,046 




1 13 


55,040 


3.22 


1 54.269 


17,100 


25 


1 8 1/2 


39,450 


3.06 


1 40,949 


12,802 




1 12 + 


45,440 


1 3.17 


1 45,531 


14,334 




1 121/2 


27,900 


! 2.76 


1 32,113 


10,110 




1 13 


43,940 


1 3.04 


1 45,873 


14,454 


26 


1 8 1/2 


50.280 


1 3.02 


1 52,994 


16,649 




12+ 


46,200 


1 3 . 13 


1 46,893 


14,760 




13 

1 


40,100 


! 2.95 


1 43,148 


13,614 



VITRIFICATION RANGE AND DI-ELECTRIC T^EHAVIOR. 



15 



TABLE II— Continued. 



1 


Cone 


Total Punc. 


Thickness 


Punc. ?/i in. 


Punc. 


N,. , 


Vokage 


mm. 


Volts 


Volts per mm. 


B 27 


12 


27,900 


( 

3.17 


27,956 


8,801 




12+ 


46,830 


3.07 


48,422 


14,928 




121/2 


55,480 


3.13 


56,312 


17,725 




13 


45,250 


3.04 


47,241 


14,885 


28 


12 + 


33,810 


3.27 


32,830 


10,340 




121/2 


34,140 


3.16 


34,311 


10,804 




13 


33,050 


3.22 


32,627 


10,264 


29 


eva 


47,040 


2.96 


50,427 


15,892 




9 


43,310 


3.12 


44,090 


13,881 




12+ 


32,000 


3.40 


29,888 


9,412 


30 


61/2 


44,680 


3.07 


46,199 


14,554 




9 


42,500 


3.06 


44,115 


13,888 




12 + 


41,900 


3.35 


39,721 


12,508 


31 


6% 


40,120 


3.16 


40,320 


12,728 




9 


36,620 


3.14 


37,060 


11,662 




12+ 


28,500 


3.09 


29,270 


9,223 




13 


36,620 


3.12 


37,279 


11,737 


32 


7% 


49,620 


3.07 


51,307 


16,163 




9 


38,440 


2.80 


43,630 


13,730 




12^4 


51,500 


3.25 


50,316 


15,850 




13 


35,100 


2.85 


39,101 


12,315 


33 


1% 


44,120 


3.10 


45,179 


14,232 




12 


42,860 


2.93 


46,417 


14,631 




121/, 


43,940 


3.17 


44,028 


13,861 


34 


12 


44,680 


2.96 


47,897 


15,894 




12 + 


48,740 


3.15 


49,130 


15,473 


35 


12 


35,480 


3.22 


34,981 


11,020 




12+ 


45,440 


3.06 


47,167 


14,850 


36 


61/2 


30,120 


3.02 


31,626 


9,973 




T% 


43,220 


3.03 


45,251 


14,264 




1214 


33,200 


2.96 


35,590 


11,216 


37 


6 


42,860 


3.02 


45,003 


14,192 




7% 


35,100 


3.13 


35,627 


11,215 




12 + 


37,480 


3.24 


36,730 


11,537 


38 


6 


32,150 


2.95 


34,593 


10,900 




61/2 


30,980 


2.98 


32,995 


10,396 




9 


50,280 


2.90 


55.057 


17,340 




12 


36,620 


3.23 


35,997 


11,338 




12 + 


43,580 


2.97 


46,543 


14,673 


39 


9 


41,800 


2.97 


44.642 


14,110 




12 


45,250 


3.13 


45,929 


14,457 


40 


12 


40,700 


3.05 


42,369 


13,344 


41 


12 


38,980 


3.03 


40,612 


12,864 


42 


6 


36,810 


2.91 


40,160 


12,650 




81/2 


34,940 


3.05 


36,373 


11,455 




12 


36,430 


2.90 


39,891 


12,560 


43 


12 


43,400 


3.12 


44,181 


13,910 




12+ 


40,500 


3.21 


40,055 


12,617 


I 


12 y2 


53,340 


3.04 


55,687 


17,546 



16 



VITRIFICATION RAXGE AND DI-ELECTRIC BEHAVIOR. 



TABLE II— Continued. 



1 




Total Punc. 


ThickQcss 


Punc. Vi ID. 


Punc. 


Xo. 


Cone 


Voltage 


mm. 


Volts 


Volts per mm. 


1 

B 44 


12 + 


45,060 


2.98 


47,989 


15.121 




12^ 


47,040 


2.93 


50,944 


16,054 


45 


12 


43,220 


3.00 


4.5,727 


14,406 




12+ 


44,490 


2.87 


49,206 


15,502 


46 


12 


44,870 


3.08 


46,261 


14,570 




12+ 


51,900 


3.06 


53,872 


16,961 




12 y* 


48,040 


3.06 


49,865 


15,686 


47 


12 


34.140 


2.17 


49,947 


15.733 




12 Va 


37,960 


2.04 


58,956 


18,608 


48 


12 


36,240 


3.07 


37,472 


11,805 




12% 


34,460 


2.89 


37,837 


11,924 


49 


6 


40,500 


3.01 


42.687 


13,455 




SVa 


38.280 


2.95 


41,189 


12,976 




12 


38,280 


2.91 


41,763 


13,155 


50 


81-^ 


43,400 


2.85 


48,348 


15,228 




12 


43,400 


2.97 


46,351 


14,613 


51 


12 


46.200 


2.76 


53,176 


16,740 




1214 


56,800 


2.68 


67,308 


21,194 


52 


12 


38,280 


3.06 


39.735 


12,510 




13 


45,820 


3.15 


46.186 


14,546 


53 


12 


44,680 


2.85 


49,774 


15,681 




1214 


37,160 


2.91 


40,542 


12,770 




13 


52,500 


3.06 


54,495 


17,157 


54 


12 


38,980 


2.66 


46,542 


14,654 




12 Va 


39,740 


2.70 


46,734 


14,720 




13 


40,120 


2.68 


47,542 


14,970 


55 


12% 


44,680 


2.83 


50,132 


15,788 




13 


45,440 


2.78 


51,983 


16,345 


C 1 


12 


22,000 


3.13 


22,330 


7,028 


2 


11 


45,440 


3.35 


43,077 


13,564 




12 


45,440 


3.20 


45,076 


14,200 


3 


7% 


30,980 


3.27 


30,082 


9,474 




11 


44,120 


3.28 


42,808 


13,451 




121/4 


46,200 


3.12 


47,031 


14,808 


4 


11 


36,050 


2.88 


39,727 


12,518 




12 


44,300 


2.18 


50,059 


15,765 


5 


11 


37,960 


3.34 


36,100 


11,365 




12 


41,100 


3.22 


40,425 


12,764 




1 12+ 


48,300 


3.00 


51,101 


16,100 


6 


( 11 


54,600 


3.22 


53,836 


16,956 




12% 


53,760 


3.16 


54,029 


17,013 




12 Vz 


44,680 


3.26 


43,517 


13,706 


7 


11 


45,820 


3.16 


47,038 


14,500 




12 


60,060 


3.77 


50,571 


15,931 


8 


12 


27,300 


3.25 


26,672 


8,400 


9 


12 

12% 





_ 








10 


12 




_ 






11 


12 


3. 5 ,'4 80 


3.54 


3i,'826 


10,023 



VITRIFICATION RANGP: AND DI-ELECTRIC BEHAVIOR. 



17 







TABLE II— Continued. 






No. 


Cone 


Total Pane. 
V'oliaje 


Thickness 
mm. 


Pjnc. 'A in. 
Volts 


Punc. 
Volts per mm. 


C 12 


7% 


1 

25,-580 


1 

2.54 i 


1 

31,975 


10,071 




11 


43,940 


2.50 i 


55,804 


17,576 




No Cone 


46,200 


2.65 


55,343 


17,434 


13 


11 


42,300 


2.44 


55,575 


17,374 




121/2 


33,820 


2.32 


45,166 


14,577 




No Cone 




1 








marked 


42,100 


2.60 1 


51,404 


16,192 


14 


11 


41,100 


2.76 1 


47,806 


14,891 




IS 


47,040 


2.52 


59,270 


18,666 




No Cone 


44,300 1 


2.49 


56,533 


17,791 


15 1 


11 


31,320 


2.73 


36,457 


11,469 




121/2 


46,410 


2.71 


54,393 


17,125 


16 


7% 


29,940 


2. 58 


36,826 


11,605 




11 


37,100 


2.54 


46.450 


14,630 




121/2 


55,920 


2.51 


70,739 


22,278 


17 j 


121/, 


31,660 


2.. 55 


39,317 


12,415 


18 


12 

121/2 










19 


121/2 

13 








'.'.'.'.'.'. 


20 


12% 










21 


12i/o 


32,600 


2.47 


41.923 


13,198 


22 


13 


30,300 


2.63 


36,522 


11,521 


23 


121/2 


33,200 


2.31 


45.617 


14,372 




13 


22.680 


2.61 


27,579 


S,G90 


24 


12 V2 


34,140 


2.71 


40,012 


12,598 


25 


121/2 


28,050 


2.63 


33,829 


10,666 


26 


12 
13 










27 


12 

12 + 
13 




:::: 






28 


12 + 
No Cone 











29 


121/2 


29,940 


2.68 


3.5,479 


ii,172 


30 


12 


32,300 


2.24 


45,769 


14,420 




121/, 


28,050 


2.29 


38,877 


1 12,250 




13 


35,100 


2.36 


47,245 


! 14,877 


31 


12 








1 




121/2 


32,600 


2.55 


40.587 


12,784 




13 


32,000 


2.31 


1 43,968 


13,853 


32 


12 


25,720 


1 2.42 


1 33,770 


10,628 




13 


23.700 


2.15 


! 34,881 


11,023 


33 


12 




1 


! 


1 


34 


! 12 






1 




35 


12 

i IB 






1 





36 


12 


24,720 


2.39 


.33.828 


' 10,343 


37 


12 


24,210 


2.73 


! 28,180 


1 8,872 
1 



18 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



TABLE II— Continued. 







Total Punc. 


Thickness 1 Punc. 5'8 in. 1 


Punc. 


No. 




Voltaee 


mm 


Volts 


Volt» per mm. 


1 

C 38 1 


13 


30,640 


2.35 


41,395 


13,038 


39 


13 


27,300 


2.2C 


1 37,838 


11,921 


40 


12 






1 




41 


12 






1 




42 


12 


28,050 


2.3f 


> ! 37,755 


ii,886 




13 


27,300 


2.3J 


L 1 37,500 


11,818 


43 


12 


22,680 


2.4J 


1 29,892 


9,410 


44 


12 











45 


12 
13 






! 




46 


12 










47 


12 






i 




48 


12 










49 


12 


22,060 


• 2.2] 


L 31,592 


9,955 


50 


12 










51 


12 










52 


12 










53 


12 










54 


12 










55 


12 










D 1 


6 

121/2 

13 












2 


6 


29,040 


2.1' 


1 42,385 


13,382 




8V2 


28.200 


2.1 


J 1 41,257 


13,000 




12+ 


32,600 


2.1 


? 1 48,574 


15,305 


3 


6 


31,070 


2.3 


? 1 41,416 


13,055 




81/2 


31,660 


2.3 


5 ] 42,203 


13,302 




124- 


28,860 


2.7 


J 1 33,593 


10,571 


4 


6 


29,940 


2.4 


7 38,500 


12,121 




81/2 


31,830 


2.4 


B 40,774 


12.835 




12 


39,740 


2.3 


S 1 53,490 


16,839 




12 + 


28.200 


2.5 


2 1 35,532 


11,190 


5 


81/0 


33,350 


2.3 


i i 45,423 


14,313 




12 


30,300 


2.1 


5 .1 44,722 


14,093 


6 


SYz 


33,:i00 


2.1 


S i 48,372 


15,230 




12 


34,780 


1 2.1 


5 1 51,335 


16,177 




13 


29,400 


> 2.3 


5 1 39,620 


12,510 


7 


8% 


28,680 


2.2 


8 1 39,923 


1 12,580 




12 


H7,160 


2.4 


2 1 48,791 


15,351 




13 


35,670 


2.2 


5 ! 50,295 


15,851 


8 


7% 


30,810 


2.1 


2 1 46,153 


14,533 




12 


30,810 


i 2.3 


2 1 42,148 


1 13,280 




121/2 


31,510 


! 2.2 


2 1 45,059 


i 14,194 




13 


33,500 


2.7 


9 i 38,190 . 


12,007 


9 


SVz 


31,660 


2.2 


8 ! 40,071 


13,886 




12 


36,240 


1 2.1 


4 1 53,780 


16,934 


10 


1 12+ 


! 29,220 


2.4 


1 1 38,512 


12,124 




1 12 1/, 


26.680 


2.3 


1 36,818 


1 11.600 




1 n 


27.300 


' 2.2 


6 1 38,329 


1 12,080 



VITRIFICATtON RANGE AND DI-EbECTRTC BEHAVIOB. 19 

TABLE II— Continued. 







Total Punc. 


Thickness | 


Punc. Vs in. 


Punc. 


No. 

1 


Cone 


Voltage 


mm. 


Volts 


Volts per mm. 


D 11 


13 










12 


evz 


34,466 


2.18 


56,268 


15,867 




8 1/2 


28,860 


2.14 


42,828 


13,486 




12 


36,620 


2.22 


52,367 


16,495 


13 


8V2 


39,740 


2.38 


52,973 


16,699 




9 


27,300 


2.22 


38,039 


12,297 




12 


30,300 


2.13 


45,147 


14,225 


11 


121/2 


27,000 


2.09 


41,013 


12,918 




6 


29,940 


2.21 


42,994 


13,547 




7% 


35,860 


2.09 


54,471 


17,158 




8% 


37,320 


2.10 


56,428 


17,771 


15 


6 


25,560 


2.22 


36,551 


11,513 




7% 


30,470 


2.04 


47,411 


14,936 




12 


28,500 


2.72 


31,770 


10,477 


16 


734 


32,900 


2.17 


48,133 


15,161 




8V2 


25,720 


2.12 


38,529 


12,132 




12 


36,810 


2.56 


45,644 


14,378 




13 


31,320 


2.31 


43,034 


13,558 


17 


7% 


30,640 


2.19 


44,428 


14,000 




12 


30,300 


2.19 


33,935 


13,825 




12 + 


32,750 


2.18 


47,717 


15,023 




13 


37,320 


2.30 


51,502 


16,226 


18 


81/2 


29,940 


2.06 


46,138 


14,534 




12 + 


33,050 


2.18 


48,154 


15,160 




13 


33,500 


2.16 


49,245 


15,510 


19 


12 + 


31,050 


2.27 


43,208 


13,679 




121/2 


34,140 


2.04 


53,122 


16,735 




13 


32,900 


2.28 


45,797 


14,430 


20 


121/2 












13 


37,320 


2 '.76 


42,955 


i3,'522 


21 


6 1/2 


32,000 


2.62 


38,752 


12,214 




8 1/0 


39,450 


2.60 


48,168 


15,173 




12 + 


42,100 


2.56 


52,204 


16,445 


22 


61/2 


26,360 


2.19 


38,222 


12,037 




7%' 


31,660 


2.19 


45,907 


14,457 




12 f 


33,500 


2.37 


44,890 


14,135 


23 


6 












9 
12+ 


29,580 


2.32 


46,465 


12,750 




26.'686 


2!68 


46,714 


i2,'827 




13 


31,660 


2.27 


44,261 


13,950 


24 


8y2 


29,940 


2.23 


42,635 


13,426 




12 


38,980 


2.29 


41,358 


13,037 




12-)- 


30,300 


2.36 


40,784 


12,398 


25 


12 + 


37,960 


2.09 


57,661 


18,162 




121/2 


36,810 


2.06 


56,724 


17,869 




13 


36,620 


2.27 


51,195 


16,132 


26 


12+ 


43,220 


2.70 


50,827 


16,008 




13 


42,860 


2.75 


49,460 


15,585 



20 VITRIFICATION RANGE AND DI-ELECTRIC BliHAVIOR. 

TABLE II— Continued. 







Total Pane. 


Thickness 


Punc. yi in. 


Pane. 


Nj. 


Cone 


Voltage 


mm. 


Volts 


Volts per mm. 


D 27 


12 


27,900 


2.68 


33,002 


10,411 




12+ 


39,740 


2.60 


48,523 


15,245 




13 


38,980 


2.58 


47,945 


15,110 


28 


13 


29,220 


2.69 


34,480 


10,862 


29 


6 
9 












12 


36,240 


2.52 


45,662 


14,381 




12 + 


35,100 


2.62 


42,516 


13,397 


30 


6 
6% 












12 


36,620 


2^48 


46,910 


14,766 




12 + 


37,960 


2.71 


44,472 


14,007 




13 


46,010 


2.62 


55,218 


17,561 


31 


61/2 




.... 








12 


36,620 


3!i3 


37,169 


ii,Voo 




13 


35,480 


2.84 


39,667 


12,493 


32 


6 


43,940 


2.55 


54,705 


17,231 




11 


46,200 


2.49 


58,951 


18,554 




12 


35,100 


2.49 


44,788 


14,092 




124- 


42,300 


2.73 


49,237 


15,494 




121^ 


49,180 


2.58 


60,491 


19,062 




13 


39,360 


2.71 


46,130 


14,524 


33 


11 


27,600 


2.78 


31,574 


9,928 




12 


32,600 


2.63 


39,316 


12,375 




12i/o 


45,060 


2.61 


54,793 


17,263 


34 


10% 


29,040 


2.60 


35,458 


11,170 




121/2 


36,620 


2.56 


45,409 


14,305 




13 


37,960 


2.67 


45,135 


14,217 


35 


IOV2 

12 + 




.... 









121/2 


25,720 


2!8r 


28,446 


" 8,961 


36 


6 1/2 













11 


36,240 


2^24 


51,3.52 


16,180 




121/2 


32,450 


2.67 


38,583 


12,154 




13 


39,740 


2.66 


47,450 


14,940 


37 


6 1/2 












101/2 


26,680 


2!75 


30,V89 


9,702 




12+ 


28,500 


2.62 


34,514 


10,878 




13 


24,380 


2.68 


28,890 


9,097 


38 


QV2 












101/2 


30,030 


2!72 


35,075 


ii,140 




13 


31,660 


2.79 


36,092 


11,348 


39 1 


ini'i 


25,920 


2.70 


30,247 


9,526 


i 


12 -C 


32,900 


2.63 


39,677 


12,510 


1 


121/2 


32.600 


2.60 


39,805 


12,540 


1 


13 


33,820 


2.83 


37,941 


11,950 


40 1 


10 v. 





1 






; 


121/i 


32,600 


2.83 


37,846 


li.Vio 


1 


13 


26,360 


2.65 


31,569 

1 


9,947 



I 



VITRIFICATIOX UAXGE AND DI-ELECTRIC BEHA\ lOR. 



21 



TABLE II— Continued. 







Toal Punc. 


Thickness 


Punc. Vs in. 


Punc. 






Voltage 


mm. 


Volts 


Volts per mm. 


D 41 


1 

! 10-/2 


I 










12 1/2 


27,606 


2.86 


36,636 


9,650 




13 


1 27,000 


2.63 


32,562 


10,266 


42 


6y2 


' 










13 
11 


23,700 


2.74 


27,468 


8,656 


43 


23,V()6 


2.68 


28,085 


8,840 




121/2 


29,400 


2.56 


36,456 


11,484 




13 


30,640 


2.66 


36,584 


11,519 


44 


11 


25,230 


2.96 


27,047 


8,524 




121/0 


30,120 


2.70 


35,421 


11,192 




13 


27,150 


2.64 


32,634 


10,284 


45 


101/^ 
11 


, 

;;;;;; 










12+ 


32,000 


2.51 


40,480 


i2,749 


45 


12^ 


34,780 


2.55 


43,301 


13,640 




13 


32,900 


2.54 


41,125 


12,953 


46 


11 












13 


32,666 


2.52 


41,076 


12,932 


47 


121^ 


23,700 


2.64 


28,487 


8,977 




13 


24,200 


2.54 


30,250 


9,527 


48 


121/2 
13 










49 


61/0 
1014 















13 


27,900 


2.76 


32,113 


10,109 


50 


101^ 













121/2 


23,700 


2.69 


27,966 


8,816 




13 


22,000 


2.48 1 


28,182 


8,871 


51 


10% 
11 





1 








13 


28,200 


2.58 


34,686 


16,936 


52 


121/2 


24,760 


2.67 


29,440 


9,273 




13 


28,350 


2.50 1 


36,005 


11,340 


53 


121/2 


25,060 


2.69 : 


29,571 


9,316 


54 


12 V2 




.... 1 








13 


25,466 


2.84 1 


28,397 


8,944 


55 


121/2 




.... 1 








13 


27,750 

1 


2.63 1 

1 


33,467 


16,552 



Vitrification Range. 

A. Georgia Kaolin. In Fig. 2 we find plotted tliree 
temperature areas, cone 7-9, cone 0-10, and cones 10-13. 
Brief inspection shows that this kaolin has a conipara- 
tivelv large range of compositions yitrifying below cone 10. 



22 VITEIPICATION RANGE AND DI-ELECTRIC BEHAVIOR. 

This is again IJlustrated b}- the fact that within this tem- 
perature range a feldspar content as low as 18 per cent, 
with 51% of clay, is shown. With a temperature corres- 
ponding to cone 13 and the same clav content, the feldspar 
may be cut down to 14%. The dividing line between the 
cone 9-10 and tlie 10-13 areas shows a decrease in feldspar 
and a corresponding increase in flint from the 25% to the 
20% feldspar line. 

B. Tennessee Ball Clay, Pig. 3. The less refractory 
character of this clay is indicated by the large range cov- 
ered by the temperature area below cone 10. Near the 
50% clay line the feldspar drops as low as 13%, and at the 
00% clay line a feldspar minimum of 5% is shoAvn at a 
temperature not exceeding cone 10. It is evident, there- 
fore, that in a body the feldspar content may be the lower 
the greater the content of ball clay. 

C. The North Carolina Kaolin offers quite a contrast 
to the last material, inasmuch as its vitrification area is 
quite small at temperatures up to cone 10. Fig. 4. The 
range is decidedly increased at the higher temperatures, 
and at cone 131/2 it is possible to cut down the feldspar 
percentage to below 15%, while at cone 10 the minimum 
feldspar content is 23%. 

D. The EnfjUsh China Clay, Fig. 5, differs from tlie 
preceding clays in that its vitrification boundaries slope 
far more gradually in spite of the fact that its alkali con- 
tent is not greater than that of the North Carolina kaolin. 
With decreasing clay and increasing flint content the spar 
gradually diminishes until, with 50%> clay, the feldspar is 
reduced to 15% at cone 9-10 to 5% at cone 10-11. It is 
evident, therefore, that this material differs considerably 
from similar American claj^s in this respect, due to its 
structure or fineness of grain. Its vitrification area is 
quite large. 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 23 



BLEININGEBi: STULU 




TnANS. AM. CER.SOC.VCLW 



LEIN1N0£R X STULL. 




24 VITRIFICATION RANGE ..VND DI-ELECTRTO BEHAVIOR. 



TR/'-'S, AM. CER. SOC VOL.Xll 



BLEININCER X STULL 




TRANS. AM. CER. &0C. VOL XII 



SLEININGER k STULL. 




VITRIFICATION RANGE AND DI-ELEGTRIC r.EJIAVKJK. 25 

Chemical Vitrification Range. 

A. Georgia Kaolin. From this cliagriim. Fig. 0, we 
learn that the minimum and maximnm limits of SiOo for 
cone 9-10 are 5.00 and 3.1 molecular equivalents. The 



TRANS. AM. CER. t^OCVOLAl. 



BLEININfiER k 5TULL. 



5.80 

5.60 
5.40 
b.lO 
5.00 



4.60 
4.40 
4.Z0 



.■^3.80 
^3,60 
^ 3.40 






Z.40 
2.20- 



2.10 



















O 


























1 














































Fio.6 ^ 


— 










( 












J 
































































1 1 1 
















1 












< 








^ 












1 




























/ 








^ 


^ 















































/ 






A 

















































y 


' 




/ 


H 










o 




























o 










/ 












o 










o 






























^ 


/ 








o 














































V 


' 


1 


, ^ 


\ 




1 r 


































/ 


^Cofie&l 


O-JJ 


^ Cones 3 -10 








r/ 














o 








\ 




1 , , 




\ 






o 

1 








/ 




( 






_ 


_ 


^_ 




o 





> 


\ 







_, 









5 


^ 




_ 




—6 


_ 


^ 


/ 












— 


— 


— 






~o" 




-Q- 


V 


^ 


V, 




^ 


— 





— 


— 


^ 




= 


— 




- 


— 








— 
















O 


, 


^ 




^ 


°^ 


















































c 








^ 


k. 













































































































































,05 .06 .07 .03 .11 .13 .15 .17 .13 .21 .23 .25 17 13 
Equivalents HO . "^i^O^- /. 



.31 2y 



minimum RO for the same temperature is 0.18. At cone 
13 the maximum SiO. is 5.42 equivalents, the minimum 
2.7, while the minimum RO is practically 0.12 equivalents. 
B. The Tennessee Ball Clay areas, Fig. 7, appear to 
be decidetlly irregular in chai'acter. It is noted that at 
cone 9-10 the maximum SiOo is decidedly higher and the 
iiiinimum quite lower than for tlie preceding clay, the 
limits heing 5.7 and 2.6 respectively. It is a curious fact 
tliat the minimum RO is much less than in the Georgia 
kaolin, it being 0.14 at cone 10 and 0.09 at cone 13. It 
would seem then that tlie ferric-oxide which is not in- 
cluded in the RO is a decided factor in bringing about 



26 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



vitriflcation in this clay. Wliile the total FooOa in the 
ball clay is not much greater in amount than in the Geor- 
gia kaolin, it is fair to assume from the physical appear- 
ance of the former that the iron oxide is disseminated 
more uniformly and is more thoroughly incorporated in 
the clay substance. As to the peculiar shape of the vitri- 
tication areas it is evident that they permit of no general- 
ization, and must be ascribed to differences in the heat 
treatment which are practically inevitable under the 



TRANS, AM.CER.SOC.VOLXII. 



BLEININuER k STULL 



6.00 
■5.80 
5.60 
5.+0 
5.20 
3.00 
4.80 
4.60 
4.40 
4.20 

'O 3.80 

^ifco 

I 5.40 
g 3.20 
■^ 3.00 
^l.U 
'^ Z.60 

240 

ZiO 

"".OB .06 .07 .09 .11 .13 .15 .17 .19 .21 .23 25 .27 .2? .31 .51 

Equivalents nO ai^O.-l 

usual conditions of test kiln practice, even though all 
possible precautions are taken. 

C. More symmetrical conditions prevail with the 
North Carolina Kaolin series. Fig. 8. At cone 940 the 
highest SiOo content in these mixtures is 4.85 equivalents, 
the minimum 3.40, while the minimum RO is 0.295. The 
cone 12-131/2 area it will be observed is very large, indi- 
cating that the proper development of such a kaolin body 
would be obtained only at the higher temperatures, just as 
was shown in the triaxial diagram. 

























































o 












/ 




















no.r : 
























/ 



















































\ 
















' 1 










t 























' 


s, 






— -, 


- 






























/ 






















































^ 














o 






, 




o 




























( 


/ 


/ 

















i 


o 








k^ 


- 


























/ 




o 














\ 


V Co7?es 7-J> 


























/ 


Cones 10-13 


\ 


Cones 3-/0 ^ 


^ 




























1 
































o 










o 




























/ 








( 


o 


-<». 










o 










> 








o 


\ 






o 








/ 






o 


J 








o 










> 


















\ 








1 








^ 


y 














> 


























< 











y 


\^ 






< 










Cones 4-7 
























-^ 


/ 


1 


/ 




o 
















































( 


/ 


4 




























































' 


















































































































































VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



27 



fc.CO 
5.80 
5.60 
5.+0 
5.Z0 
5.00 
4.80 
4.60 

4.00 

^ 3.e0^ 

I 3. 

-^ 3.Z0 

§ 3.00 

'g^ IM 

'^2iO 

2.40 

ZiO 

2J30 



TRANS. AM. CER. &0C. VOUO 



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28 



VITRIFICATION R.4NGE AND DI-ELECTRIC BEHAVIOR. 



D. Fig, 9. The English China Clay limits for cone 
10-12 are 5.40 maximum SiOo, 2.75 minimum SiOg and 
0.16 minimum RO. For cones 12-13^,^ the maximum SiOs 
is 5.55, the minimum SiOo 2.35, and the minimum RO 
practically 0.11. 

Porosity Coordinated with Feldspar-Flint Contents, 
— the clay being kept constant, at cone 9-10. 



TRANS. AM. CER. SOC VOLXII. 



BLEININ6ER i STULL 



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5 
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25 



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40 

10 



5% Flint 



1. 50% Clay, Fig. 10. This diagram shows at once 
the percentages of feldspar necessar^^ to bring about vitri- 
tication at this temperature. For the Georgia kaolin this 
point is about 24%, for the Tennessee ball clay less than 
15%, for the N. 0. kaolin 25%, and the English China 
clay about 15%. As far as the ball clay and the English 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



29 



China clay are concerned, the feldspar-flint additions are 
of the nature of refractory agents. The feldspar is dis- 
tinctly a flux for the N. C. kaolin but very much less so 
for the Georgia kaolin. 

2. 60% Chui, Cone 9-10, Fig. 11. Here the true na- 
ture of the various claj^s is more clearly represented, and 
brief inspection shows that the N. C. kaolin is by far the 



TRANS. AM. CER. 50C. VOL.XII . 



BLEININGER i: STULL 



19 
18 

17 

15 
14 
13 
12 
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A 
D 

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5% Fliiit 



most refractory material which even with maximum 
amount of flux fails to produce a dense body at this tem- 
l>orature. AVith 60*^^ clay any i)ossible combination of spar 
and flint cannot bring about vitrification. The eutectic 
]»oint of N. C. kaolin-spar as well as of N. C. kaolin — 75% 
pure spar+25% flint mixture — is beyond cone 0-10. 



30 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



Porosity-Temperature Diagrams. 

I. 50% Clay. 

Series A, Georgia Kaolin, Fig. 12. These curves pre- 
sent the rate of vitrification, and we note that for the mix- 
tures Nos. 2, 4, 6 and 8 vitrification proceeds most rapidly 
between cones 4 and 6, while for Nos. 10 and 11 the same 
action occurs only beyond cone 11. 

It is fair to assume then that the active fluxing magma 
in all bodies but No. 11 has a melting point between cones 



38 
36 
34 

3Z 

^ (1 


TRANS. 


AM. CER.SOC.VOLXi;. 














BLEININGER & STULL. 
























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4 and 6, and it is entirely possible to find its composition 
by running a series of the system 0-50% clay, 50-0% feld- 
spar+flint. From the large part of the pore space filled 
up during this short temperature interval it appears also 
that the fluxing matter has a lower viscosity than at any 
subsequent stage. For while at higher temperatures the 
total amount of the igneous solution is greater as it en- 
riches itself in silica and alumina, the viscosity increases 
correspondingly, causing it to flow less readily and more 
liable to form a bleb structure. It is for this reason that 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



31 



TRANS. AM. CER. 5CC. VOLXII. 



BLEINIINGER Sc STULL. 



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30 
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TRANS. AM. CER. SOC. VCL.Xll 



SLEININGER Jfc 5TULL. 




0' I 2 3 
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IZ 13 



32 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



TrtANS. AM. CER. 50C. VOLXII . 



BLEININQER & 5TULL. 



38 
36 
34 
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\Z 13 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 33 

the addition of a small amount of lime is beneficial, inas- 
much as it decreases the viscosity and hence reduces the 
above tendency. 

Series B. Tenn. Ball Clay. Fig. 13. Here the condi- 
tions are very similar excepting that the greater impurity 
of the clay causes the curves to start at lower porosities. 
Like in the preceding and all subsequent series, it is evi- 
dent that the fusing action of feldspar begins at quite a 
low temperature. 

Series C. N. 0. Kaolin, Fig. 14. The characteristic 
feature of this cla}^, its longer vitrification temperature 
range, is at once shown as is to be expected from such a 
comparatively coarse grained kaolin. While the Georgia 
kaolin in mixture No. 8 reaches vitrification betAveen cones 
11-12, the N. C. kaolin of the same mixture barely ap- 
proaches the vitrified state at cone 13. This points out a 
useful function of this material which must not be lost 
sight of, its ability to hold up a clay body. The more a 
certain composition or shape has a tendency to deforma- 
tion, the greater proportion of this kaolin c.ui be intro- 
duced to counteract it. 

Series D. Fnglish China Clag, Fig. 15. Tlie smooth 
curves indicate well the character of the vitrification pro- 
cess. It differs from the two preceding kaolins in that it 
appears to bring about better vitrifying conditions, which 
are not too abrupt between certain points, nor does it fail 
to produce vitrification with a low feldspar content like 
that of Xo. 10 of A and C. Its great fineness of grain 
undoubtedly is a factor in this behavior. 

II. 60% Clay. 

Series A. Georgia Kaolin. Fig. 16. In this set of 

curves the same observation is made as before, viz., the 

' highest rate of vitrification is found between cones 4 and 7 

but, as is to be expected, the vitrification temperatures 

have been raised with the higher clay content. 

Series B. Tenn. Ball Clag. Fig. 17. In distinction 
from the preceding clay, the vitrification temperatures are 



34 



VlTRIP^IGATION RANGE AND DI-ELECTRIC BEHAVIOR. 



THANS. AM. CER. sec. VOL.XII. 



BLEINiNuER & STULL. 



30 

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3 10 |i \l 13 



lower than with 50% mixtures, a fact to which attention 
has already been called above. 

Series C. N. C. Kaolin, Fig. IS. The vitrification 
temperatures of these mixtures are considerably higher 
than in the 50% series, and the slopes of the curves far 
more gradual in the cone 4-7 interval. 

Series D. English China Clay, Fig. 19. Here no 
radical changes are noted though the vitrification temper- 
atures have been shifted somewhat to the right. 

Specific Gravity-Temperature Diagrams. 



In figures 20, 21, 22, 28, 24, 25, 26 and 27 the fact 
that silicates undergo an increase in specific volume upon 
vitrification is shown clearly. 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



36 



TRAN5.AM. CeR. &0C.\0LX1I 



riCINi'JOER Sr 3TULL . 




40% Feldspar WlFlint 

30%. '• / 

25Z -■• HS " 

20% " t£0 " 

> +Z5 " 

. -30 " 

f3S " 



TRANS AM CER. SOC VCIXII 



BLEiNiNOER & STULL 




^2/ ~ W% Feldspar-^Oiriinf 

Z3-J0 '• 10 '■ 

Z^-Zt ■• IS : 

Z5-Z0 " 20 ■> 

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28- 6 " 35 « 



3 10 II \I \^ 



36 



VITRIFICATION RANGE ANI.> DI-ELECTRIC BEHA\10R. 



TRANS. AM.CER.SOC.VOLMI 



BLEININQER & STULL 



yn).Z ~S0%refols;iartO%f/int 
^--^0 " 10 » 

6-30 ') ZO ^ 

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9 iO !i 12 13 



£.70 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 

TRAN5. AM.CER.50C. VOLXII 6LEININ6ER XSTULL 



M.Z ~ 50 7orddiiiarW%>Flint 
^-■W " /O " 

h-30 " ZO " 

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-30 >i 20 ' 

8-20 » 30 ^ 



38 VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 

r, TRANS. AM. CER. S.OC. VQL-XII. BL ElNlN GE R JC 5TULL 



2.65 



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TRANS. AM. CER. 50C. VOL.XIl. 



BLEININGERASTULU 



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3 10 1! I^ 13 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 39 



2.70 



2.65 



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■^ Z.5 
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TFr/MNS. AM. CER. SOC.VOLXII. 



BLEiNINGEFtiSTULL 



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TftANi. AM. CER.SOC. VOLXII 



BLEINiNGER.VSTull 




01 I 2 3 4 5 6 7 
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Clay D 



10 II \l \i 



40 VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 

DI-ELECTRIC BEHAVIOR. 

In Table II the voltages required to puncture the test 
pieces are compiled, together with the burning tempera- 
tures in cones. The voltages have been arranged in three 
groups which are: Less than 10,000 volts per mm; from 
10,000-14,000 volts per mm., and from 14,000-18,000 volts 
per mm. These groups are shown in the triaxial composi- 
tion diagrams. Figs. 28, 29, 30 and 31. Of each composi- 
tion the specimen showing the highest resistance was se- 

TRANS. AM. CER.SOC. VOLXM . , BLEININQER X STULL . 



Fio.ZS 




20 25 30 35 40 4S 

Flint 
Georgia Kaolin. 

lected without regard to the burning temperatures. Tlie 
di-electric punctures seemed to locate flaws in the body 
structure with accuracy, and frequently the break would 
occur some distance away from the electric contact, 
through some jiggering defect. Eesults, in which punc- 
ture was evidently due to a flaw, were rejected. 

On comparing the di-electric strength diagrams it is 
found that the maximum voltage group is by no means 
restricted to a short range in composition but covers a 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 41 



TBANS.AM. CER. SOC.VOL.Xll. ^ y- 



BLEINlNGERkSTULL. 




North Carolina Kaolin. 



42 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 



TRANS. AM. CER. SOC. VOLXII. 



BLEININQER ic 5TULL 




5 10 15 20 Z5 30 55 40 45 

English China Clay. 
large area, in each case roughly proportional to the vitri- 
fication area. If this electrical test is acceptable, of which 
the writers are not certain, since they have no familiar 
knowledge of insulator testing, it would seem then that 
an^^ well vitrified body, free from mechanical and burning 
flaws, irrespective of composition, would be suitable for 
insulation work as far as electrical resistance is concerned. 
It is therefore more a matter of obtaining sound vitrifica- 
tion than of a certain composition. The proper selection 
and combination of the clays for best mechanical manij)u- 
lation, proper drying and normal burning and vitrification 
are the main points to be considered. In this respect it is 
evident that much can be done if the drying and burning 
behavior of each clay is thoroughlj^ understood. With a 
mixture, for instance, of Georgia kaolin, North Carolina 
kaolin, and Tennessee ball clay it would be possible to 
meet practically every condition and by adjusting the 
amount of the coarser grained materials, the drying and 
burniuir behavior could be regulated sntisfactorilv. The 



VlTRIflCATION RANGE AND DI-ELECTRIC BEHAVIOR. 43 

practice of the white v^aia potter to depend upou three or 
four materials for the introduction of his clay substance 
is a wise one, provided a i>yo\)er balance is maintained 
between clays of the ojjposite type. 

What has been said regarding the di-electric beliavior 
of porcelains at atmospheric temperatures does not. of 
course, apply to more elevated temperatures. The eJectri- 
cal resistance of porcelain rapidly decreases with increas- 
ing temperature, and at the same tiine the composition 
becomes a more and more important factor. Thus a high 
feldspar porcelain ma^' be an excellent nonconductor at 
ordinary temperature, but might break down utterly at a 
temperature of several hundred degrees C. 

Owing to the fact that graphic presentation has been 
employed througliout, the facts found are moj-e clearly 
shown by the diagrams than can be summarized in words. 
The fact tliat feldspar is a solvent and does not react chem- 
ically^ with the clay substance is again brought out clearly, 
as well as the observation that this mineral begins this 
dissolving action at a low temperature. It was shown 
also that the structure and fineness of grain of the clays 
incorporated in a body have a decided influence upon the 
vitrification process. In one case (Tennessee ball clay) 
tlie feldspar-flint mixture even behaved as a refractory con- 
stituent in the 50% clay body. From this it follows that 
the feldspar content required depends upon the individual 
clays employed and not upon the total content of so-called 
clay substance. In this way it may be possible to cut 
down the percentage of feldspar by changing one or more 
of the clays. 

Attention was called to the fact that the rate of vitri- 
fication of the various bodies was not (^onstant, but showed 
an acceleration, usually between cones 4-7. This was 
ascribed, in part, to the lower viscosity of the resulting 
fusible component at these temperatures. 

The English China clay showed a more uniform rate 
of vitrification and a greater range than the two American 
IvRolins. 



44 VITRIFICATION RANGE AND Dl-ELECTRIC BEHAVIOR. 

Vitrification is accompanied by increase in tlie speci- 
fic volume. The worlv failed to show any regular relation 
between feldspar content and burning temperature on the 
one hand and the development of vesicular structure on 
the other. 

The electrical resistance seems to depend more upon 
sound vitrification and good mechanical structure than 
chemical composition, excepting, of course, insofar as the 
latter governs the vitrifying behavior. 

The thanks of the writers are due to Professor C. W. 
Kolfe, Director of the Department of Ceramics, University 
of Illinois, for having granted the funds necessary for this 
work, and to Messrs. W. S. Williams, A. E. Williams, S. B. 
Eadcliffe and K. K. Hursh for tlieir careful work and 
faithful cooperation. 

DISCUSSION. 

Mr. Funly: I notice that you plot your results on 
basis of chemical composition, rather than mineralogical 
constitution. Are you more willing to base your deduc- 
tion on chemical composition than on mineralogical con- 
stitution? In other ■v\'ords, would it not iiave been more 
logical procedure to have plotted your data with the min- 
erals as variants rather than the oxides of which the 
minerals are comprised? 

Mr. Bleininger : The results are referred both to the 
chemical composition (from the analyses) and to the per- 
centage composition of the three constituents. No attempt 
has been made to get at the mineral composition, i. e., con- 
tent of clay substance, feldspar aad quartz in their theo- 
retical relations. 

Air. Fnrdji: In the first place, we do not know the 
exact mineralogical constitution of the commercial kaolins 
and feldspars. In the second place, such breaking down 
of originally added mineral compound, as for instance, 
kaolinite to form sillimanite will not take place in the vit- 
rified portion at tlie same temperature nor at the same rate 



i 



VITRIFICATION RAXGE AXD DI-ELECTRIC BEHiVVIOR. 45 

as they would if lieated alone, i. e., without admixture of 
other minerals. The transition from the unstable AI0O3 
2 SiOo to the stable ALO,; : SiOo occurs in porcelains much 
earlier than it would in pure kaolinite. 

Then again, the reversible transition from quartz to 
tridimite varies in rate with variation in viscosity, etc., 
of the molten solution in which the free silica is dissolved. 
In some porcelain mixtures I doubt if there is a complete 
reversal from tridimite to quartz. 

It is a fact, however, — and Professor Bleininger will 
agree with me in this — that the only decided chemical al- 
teration taking place in vitrifying porcelain is the break- 
ing down of kaolinite to the more stable form — sillimanite. 
While it is a fact also that this transformation or breaking 
down takes place in a fusion at much lower temperature 
than it otherwise would, the researches that ^[r. VN'atts 
quoted last year demonstrated that it Avas a very sluggish 
transformation. This means that in a vitrified porcelain, 
sillimanite is formed so slowly that it does not progress 
very far under the normal burning condition prevailing in 
porcelain factories. 

We may not be in position to speculate as to the exact 
constitution of the vitrified porcelain, yet we do know as 
much, if not more, about the constitution of it in this 
condition than we possibly can of it in the unburned con- 
dition. 

Jfr. Bleimnger: I do not agree ^ith Professor Purdy 
in all he says. In fact, I believe we are still fnr off from 
knowing what takes place during vitrification and fusion 
in systems involving at least three minerals, under condi- 
tions far from equilibium and infiuenced by such factors 
as difference in fineness of grain, rate of heating and cool- 
ing, etc. Again there comes in the diificulty of determin- 
ing the minerals composing the clay, feldspar and quartz, 
with any degree of accuracy. Surely, the structure of such 
clays as the North Carolina and Georgia kaolins is not 
differentiated by the present methods of mineral analysis 



46 VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 

or mineral computation. That we have realized the differ- 
ences caused by the uses of different cla^ys is shown by the 
very aim of this work where we have combined the same 
feldspar and quartz witli four different clays. I see lience 
no objection to referring the results to percentage composi- 
tion and chemical formulfe. The latter at least are based 
upon positive facts, the chemical composition obtained by 
analysis. As soon as we have methods available for min- 
eral analysis of reasonable accuracy, which do not depend 
upon an insufficient technique or theoretical calculation, 1 
am sure they will be used. 

Mr. Purdy : What I have in mind is this. If you 
should make up the body by molecular formula based on 
chemical analysis of the materials, introducing your K2O, 
etc., from different sources, would you have tlie same re- 
sults? In other words, would you base a consistent argu- 
ment or expect constant result by blending wholly on basis 
of chemical composition? Does not tlie sort of minerals 
you use have very large effect? 

Mr. Bleininr/er: I do not deny that the mineral 
structure is of importance, but the finer the constituents 
of a body are ground the less important does the initiaJ 
mineral composition become. Thus recent work has shown 
that a good porcelain bod}^ was obtained from a mixture 
of pure silica, pure alumina and alkali. Given tine enough 
grinding and long enough burning and the initial mineral 
structure will be wiped out. However, in most of our 
American bodies the initial structure persists — a fact 
which is well realized. What I wish to bring out is the 
fact that the usual calculated mineral composition and 
that obtained by the rational analysis is inaccurate and 
based upon conceptions which are not in accord with facts. 
Why not then be content with the chemical composition as 
given by analysis? As to the iinal mineral composition 
of a body very little is known. We know for instance that 
sillimanite is formed in porcelains at certain tempera- 
tures, but to use the amount of this mineral present as a 
criterion of the value of a body seems far fetched. 



VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 47 

Mr. Furdij : The point in question might be made by 
taking this case. Suppose we have the potash introduced 
through a viscous medium like feldspar, that is, viscous 
in the molten state, or through the medium of mica, or 
any other silicate which contains alkalies? We could get 
different results, or we might get the same results, with 
the same chemical composition. It dei^ends upon the vis- 
cosity of the medium through which the oxides are added 
whether the reaction is going to come to equilibrium or 
not, and the mineralogical constitution, both initial and 
final, is in my estimation much more important than the 
simple analysis of tlie body. Wo have tried some of those 
tilings this year and found that it was far more logical, or 
oui- data were followed far more easily on the simple min- 
eralogical basis, than on basis of chemical composition. 
We have come to the conclusion, therefore, that it is fool- 
ishness to write a molecular formula of the body as we do 
of glazes, because we have produced different bodies on 
the same formula. 

If you mix potash, alumina, and silica in the same 
proportion as in pure feldspar, and then frit the mix, 
you will obtain feldspar. No one questions that. Day and 
Allen did that very thing, but they had to fuse and refuse 
the mass many times before they obtained any large per- 
centage amount of feldspar from the mix used. If a feld- 
spar be thus made and used as a constituent in porcelain, 
may I ask would it not be feldspar still, although syn- 
thetically prepared? Watts imitated Cornwall stone thus, 
but he calcined his synthetic mix before attempting its 
use. You cannot add KoO, ALOo and SiOo as such and 
make a porcelain that would be like one of same composi- 
tion but made from commercial feldspar, etc. 

Tlie researches of Seger, Mellor. Simonis. Berdel, 
and of Shepherd and Ilankin, leave but little if any doubt 
that fusion in porcelain is not attended by chemical reac- 
tion between the mineral components, and that the only 
chemical phenomena noted is the formation of sillimanite 
from kaolinite. 



48 VITRIFICATION RANGE AND DI-ELECTRIC BEHAVIOR. 

Mr. BJeiniuger: It will be noticed that the results of 
the work, porosity and di-electric strength, are not re- 
ferred to the chemical composition but to the percentages 
of clay, feldspar and quartz. The chemical composition 
has been used for the purpose of classification for which 
purpose I maintain that it is closer to the facts than any 
hypothetical mineral composition. 

3Ir. Purely: There is one other point in that connec- 
tion. Of course, in the bodies we do not completely fuse 
the mix. Such a procedure would result in distorted ware. 
Synthetically made porcelain, unless made from fritted or 
calcined material, will not be of the same sort as those 
porcelains you ha^s^e exhibited here, i have seen porcelain 
glazes attempted synthetically. They were failures. The 
same would be true in porcelain bodies. While working 
in a floor tile factory, I attempted the duplication of cer- 
tain French porcelain on basis of chemical com])osition. 
I failed. The same can be said for any ceramic body and 
nearly all of the alkaline earth glazes. 

But there is one other point, feldspar in large quan- 
tities produces a vesicular structure. Have you deter- 
mined the effect of bleb structure in di-eleetric strength? 
I noticed the high strength was in the high feldspar bodies 
but the maximum feldspar was only 50%. 

Mr. Bleininger: The determinations of the true spe- 
cific gravities Avere made for the primary purpose of get- 
ting at the "bleb" structure, but we were grievously dis- 
appointed in finding that the porosity curves expressing 
the enclosed pore space were far from consistent. Roughly, 
the bleb space increased with the content of feldspar, but 
it seemed that the variations in physical structure were an 
important factor. Thus the amount of water used and the 
manipulation evidently brought about fluctuations in the 
volume of enclosed poral space. We regret exceedingly 
that we failed to show any consistent relation in this 
direction. 






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