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Full text of "Dissolved gases in glass"

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UNIVERSITY OF [ILLINOIS BULLETIN 

ISSUED WEEKLY 
[Vol. XVIII December 13, 1920 No. 15 

i Entered M second-olaes matter December 11. 1912. at the post office at Urbana. Illinois, under the act of Augmt 

24. 1912. Acceptance for mailing at the special rate of postage provided for in section 1103 

Act of October 3. 1917. authoriied July 31. 1918) 



DISSOLVED GASES IN GLASS 






BY 
EDWARD W. WASHBURN 

FRANK F. FOOTITT 
ELMER N. BUNTING 




LIBRARY 

i 10 1956 

UNIVERSITY OF CALIFORNIA 



BULLETIN No. 118 
ENGINEERING EXPERIMENT STATION 

PUBLISHED BY THH UNIVKBSITT or ILLINOIS, UBBANA 



PRICE: TWENTY CENT* 

EUBOPEAN AGENT 
CHAPMAN & HALL, LTD., LONDON 



THE Engineering Experiment Station was established by act of 
the Board of Trustees, December 8, 1903. It is the purpose 
of the Station to carry on investigations along various lines of 
engineering and to study problems of importance to professional engi- 
neers and to the manufacturing, railway, mining, constructional, and 
industrial interests of the State. 

The control of the Engineering Experiment Station is vested in 
the heads of the several departments of the College of Engineering. 
These constitute the Station Staff and, with the Director, determine 
the character of the investigations to be undertaken. The work is 
carried on under the supervision of the staff, sometimes by research 
fellows as graduate work, sometimes by members of the instructional 
staff of the College of Engineering, but more frequently by investiga- 
tors belonging to the Station corps. 

The results of these investigations are published in the form of 
bulletins, which record mostly the experiments of the Station's own 
staff of investigators. There will also be issued from time to time, in 
the form of circulars, compilations giving the results of the experi- 
ments of engineers, industrial works, technical institutions, and gov- 
ernmental testing departments. 

The volume and number at the top of the front cover page are 
merely arbitrary numbers and refer to the general publications of 
the University of Illinois : either above the title or below the seal is given 
the number of the Engineering Experiment Station bulletin or circular 
ivhich should be used in referring to these publications. 

For copies of bulletins, circulars, or other information address the 

ENGINEERING EXPERIMENT STATION, 
URBANA, ILLINOIS. 



UNIVERSITY OF ILLINOIS 
ENGINEERING EXPERIMENT STATION 

BULLETIN No. 118 DECEMBER, 1920 



DISSOLVED GASES IN GLASS 



BY 
EDWARD W. WASHBURN 

PROFESSOR OF CERAMIC CHEMISTRY 

FRANK F. FOOTITT 

SGT. 6th SERVICE COMPANY, SIGNAL CORPS, U. S. A. 

ELMER N. BUNTING 

RESEARCH ASSOCIATE IN THE ENGINEERING EXPERIMENT STATION 



ENGINEERING EXPERIMENT STATION 

PUBLISHED BY THE UNIVERSITY OF ILLINOIS, URBANA 




TA 



CONTENTS 

PAGE 

I. INTRODUCTION 7 

1. Foreword . '. 7 

2. Purpose of the Investigation 7 

3. Acknowledgments , 8 

II. DEMONSTRATION OF THE EXISTENCE OF DISSOLVED GASES 

IN FINISHED GLASS . . . .... . . 11 

4. The Method Employed . .....'.. . . 11 

5. The Glass 11 

6. The Furnace ... . 11 

7. Experimental Procedure . 11 

8. The Result . 14 

III. PARTIAL ANALYSIS OF THE GASES EVOLVED FROM THE 

GLASS . . " . . . . . 17 

9. The Apparatus and Method . . . . <" .. . 17 

10. The Analysing Train ... . . ... . 17 

11. Flushing the Furnace .......... 17 

12. Melting the Glass . . 18 

13. The Results 18 

IV. A SPECIAL APPARATUS FOR BOTH MEASURING AND ANA- 

LYSING THE DISSOLVED GASES IN GLASS . . .21 

14. Description of the Apparatus 21 

15. Determination of Free Volume of Furnace ... 21 

16. Experimental Procedure 23 

V. THE GAS CONTENT OF THREE TYPES OF COMMERCIAL GLASS 24 

17. A Barium-Flint Optical Glass . . '. . . - . 24 

18. A Light Flint Bulb Glass . 24 

o 

T77 



CONTENTS (CONTINUED) 

PAGE 

19. A Borosilicate Laboratory Glass 24 

20. Discussion of the Results 25 

VI. THE SIGNIFICANCE OF DISSOLVED GASES IN GLASS ... 27 

21. The Relation between Adsorbed and Dissolved Gas 27 

22. The Influence of Dissolved Gases upon the Proper- 

ties and Behavior of Glass 29 

23. The Use of Vacuum Furnaces in the Manufacture 

of Glass 30 

VII. SUMMARY 32 

24. Summary of Results 32 



LIST OF FIGURES 
NO. PAGE 

1. Melting Pot, with Block of Glass before Melting 9 

2. Detail of Vacuum Furnace 12 

3. Detail of Pot, Eesistor, and Insulation 13 

4. Vacuum Furnace and Large Vacuum Tank 15 

5. Melting Pot, with Block of Glass after Melting and Evacuating ... 16 

6. Apparatus for Measuring and Analysing the Dissolved Gases in Glass . 19 

7. Detail of Apparatus for Measuring and Analysing the Dissolved Gases in 

Glass . \ . , 22 



LIST OF TABLES 

NO. PAGE 

1. Per Cent by Weight of Oxygen and of Carbon Dioxide Dissolved in a 

Barium-Flint Optical Glass 18 

2. Summary of the Eesults on the Amounts of Dissolved Gases in Finished 

Glass 25 



DISSOLVED GASES IN GLASS 



I. INTRODUCTION 

1. Foreword. The work described in the following pages was 
begun in June, 1917, as part of a program of research on some of the 
problems connected with the manufacture of optical glass. The first 
experiments were carried out by Mr. FRANK F. FOOTITT, at that time 
Research Assistant in the Engineering Experiment Station. Mr. 
Footitt later joined the Signal Corps of the United States Army and 
was detailed at the University to assist in the continuation of the re- 
search. His part in the work continued until he was honorably dis- 
charged from the service in February, 1919. The results given in 
the first three chapters of the present paper are based upon Sgt. 
Footitt 's experiments, an account of which was given before the 
Pittsburgh meeting of the American Ceramic Society in February, 
1919. After Sgt. Footitt 's discharge the investigation was dropped 
until January, 1920, when it was again taken up with the assistance 
of DR. ELMER N. BUNTING, who is continuing it at the present time. 

2. Purpose of the Investigation. All varieties of glass, even at 
ordinary temperatures, are in the liquid state of aggregation. They 
are liquids which have been cooled through their normal crystalliza- 
tion interval so rapidly that there has not been time for crystallization 
("devitrification") to occur. Instead, the viscosity of the liquid has 
been increased to such a large value that the molecules do not have 
sufficient freedom of motion to permit the rearrangements necessary 
for the formation and growth of crystals. The liquid has thus been 
supercooled until it has become a solid. In principle any liquid can 
by supercooling be brought into the condition of a glass, but since 
it still remains a liquid, it should possess the characteristic properties 
of liquids, including the power to hold gases in a state of solution. 

During the process of manufacturing glass, large quantities of 
gas, mainly carbon dioxide, oxygen, and nitrogen, are evolved from 



"8 ILLINOIS ENGINEERING EXPERIMENT STATION 

the batch owing to the occurrence of chemical reactions such as the 
following : 

Na 2 C0 3 + Si0 2 = Na 2 Si0 3 + C0 2 

4 KN0 3 + 2 Si0 2 = 2 K 2 Si0 3 + 2 N 2 + 50 2 

2 Pb0 2 + 2 Si0 2 = 2 PbSi0 3 + 2 

If ammonium nitrate, NH 4 N0 3 , is employed in "blocking"* the 
glass, water vapor will also be evolved during the fining. The glass 
will thus be saturated with these gases at the partial pressures which 
prevail at the end of the "fining" operation. 

On cooling the glass, these gases should remain in solution, and 
glass in the finished state may therefore be expected to contain appreci- 
able quantities of these dissolved gases. Since no actual data concern- 
ing the nature or amounts of such dissolved gases were available, the 
experiments described below were undertaken for the purpose of 
throwing some light on this question. These experiments are to be 
regarded as preliminary to a more extended investigation of these 
dissolved gases, and of their influence upon the properties of the 
finished glass, and its behavior during use. 

In addition to the account of the experiments conducted to date, 
and their results, there will be found in the following pages some dis- 
cussion of the relation between adsorbed and dissolved gas, the in- 
fluence of dissolved gases upon the properties and behavior of glass, 
and the use of the vacuum furnace in the manufacture of glass. 

3. Acknowledgments. For samples of glass used in the present 
investigation we are indebted to the United States Bureau of Stand- 
ards, and to the Pittsburgh Plate Glass Company. The Signal Corps, 
and later the Aircraft Production Board, made possible the prosecu- 
tion of the work during the war by the detail of Sgt. Footitt as Re- 
search Assistant. 



* The term "fining" or "plaining" is applied to the operation of eliminating bubbles 
from the molten glass. This may be accomplished by heating the glass to a sufficiently high 
temperature to cause the bubbles to expand and rise to the top of the melt. If this method 
is not effective the operation of "blocking" is employed. This consists in inserting into the 
melt, with the aid of an iron rod, a potato, a piece of green wood, a pellet of ammonium 
nitrate, or in general any material which will give a copious evolution of gas in the form 
of large bubbles which will rise through the melt and gather up the small bubbles in their 
path. 




FIG. 1. MELTING POT, WITH BLOCK OF GLASS BEFORE MELTING 



DISSOLVED GASES IN GLASS 11 



II. DEMONSTRATION OF THE EXISTENCE OF DISSOLVED 
GASES IN FINISHED GLASS 

4. The Method Employed. In order to demonstrate the ex- 
istence of dissolved gases in considerable quantity in a piece of per- 
fectly clear homogeneous glass, the method of " sudden evacuation" 
may be employed. In this method the piece of glass to be investigated 
is melted under atmospheric pressure in a vacuum furnace which can 
be connected through a valve to a large - evacuated tank. When the 
temperature of the glass has reached about 1200 deg. C. the valve is 
opened quickly, thus causing a sudden drop of pressure within the 
furnace. 

This experiment is similar to the opening of a siphon of soda 
water, and if the glass contains dissolved gases a similar result would 
be expected, that is, there should be a sudden evolution of gas from 
the glass, causing it to expand in volume and to effervesce vigorously. 

5. The Glass. The glass employed in the first experiment was 
a piece of barium flint optical (1.6053-43.6) having the following 
composition, as determined by the Bureau of Standards: 

Oxide . . . Si0 2 As 2 5 PbO ZnO BaO K 2 
Mole (per cent) 64.5 0.15 9.73 9.22 10.2 6.24 

A piece free from bubbles was selected, placed on a table beside 
an inverted melting pot, and photographed. (See Fig. 1.) 

6. The Furnace. The vacuum furnace and the details of the 
heating element and thermocouple installation are shown in Figs. 
2 and 3, which are self explanatory. The outlet tube was connected 
to a Nelson rotary vacuum pump and also, through a valve, to a 
large vacuum tank (A, in Fig. 4) having a capacity about 100 times 
that of the furnace chamber. 

7. Experimental Procedure. The melting pot containing the 
piece of glass was placed inside the heating chamber (Fig. 2) and 
this in turn placed within an insulating cylinder supported on the 



12 



ILLINOIS ENGINEERING EXPERIMENT STATION 




FIG. 2. DETAIL OF VACUUM FURNACE 



DISSOLVED GASES IN GLASS 



13 



Thermocouple Leads 
^-Current Supp/y 



Porce/a/n Thermocouple Tube* 



; '. ^-P/atinum He&f/rtg Co/7 



F/re-c/at/ Jcrckete 
Refractory Ce/nertf 

si 



Una /a zed ' Porce/ar/r? Pof 




FIG. 3. DETAIL OF POT, EESISTOR, AND INSULATION 

furnace base as shown (Fig. 3). The water cooled iron dome (see 
Fig. 4) was then lowered into place on its rubber gasket and the cur- 
rent started in the heating coil. When the glass had attained a tem- 
perature of about 1200 deg. C. the valve connecting the outlet with 
the large vacuum tank was quickly opened. 

This tank had been previously evacuated to a pressure of 1 inch 
of mercury, and as soon as pressure equalization had taken place, as 
indicated by the manometer, the valve was quickly closed, the Nelson 
pump started, and the pressure in the furnace chamber brought 
down rapidly to less than 1 cm. of mercury. The heating current- 
was then cut off and the furnace allowed to cool with the vacuum on. 



14 ILLINOIS ENGINEERING EXPERIMENT STATION 

8. The Result. On opening the furnace most of the glass was 
found outside of the pot, standing above it in the form of a large 
white mass of foam. This was broken away from the pot and photo- 
graphed as before, beside the inverted pot. The result is shown iu 
Fig. 5. By comparing Figs. 1 and 5 an idea of the increase in volume 
associated with the evolution of the dissolved gases may be obtained. 
This amounted to about six times the volume of the original piece. 
The existence of considerable quantities of gas in a state of solution 
in the glass was thus demonstrated. 




FIG. 4. VACUUM FURNACE AND LARGE VACUUM TANK 




FIG. 5. MELTING POT, WITH BLOCK OF GLASS AFTER MELTING AND EVACUATING 



DISSOLVED GASES IN GLASS 17 



III. PARTIAL ANALYSIS OP THE GASES EVOLVED 

FROM THE GLASS 

9. The Apparatus and Method. The furnace employed was 
that used in the preceding experiment: The large vacuum tank was 
disconnected, however, and the outlet tube V was connected to a Gaede 
high vacuum pump, through an analysing train. The method con- 
sisted briefly in evacuating the furnace until all adsorbed gases were 
removed, melting the glass, drawing the evolved gases out through 
the analysing train, and finally washing out the furnace with pure 
nitrogen. All connections throughout the system were sealed glass 
joints, or glass-to-glass joints covered with heavy rubber tubing and 
coated with a beeswax-rosin mixture. 

10. The Analysing Train. The analysing train consisted of the 
following elements in the order named, starting from the furnace end : 

(1) a series of six gas wash bottles containing standard barium 
hydroxide solution, and having their delivery tubes drawn down to 
capillary openings so as to produce a stream of small bubbles through 
the solution when in operation: 

(2) a drying tower containing pumice and sulphuric acid: 

(3) a glazed porcelain combustion tube containing copper gauze 
and provided with a heating coil. Two pieces of copper gauze previ- 
ously reduced in hydrogen and then weighed were placed in series 
in the combustion tube, which was kept at 700 deg. C. during the run. 

Before the experiment was begun the analysing train was thor- 
oughly washed out with pure nitrogen in order to remove all air. 
The nitrogen used for this purpose was purified by passing it over 
hot copper, and through wash bottles containing barium hydroxide 
solution. The nitrogen thus purified gave zero test for both carbon 
dioxide and oxygen. 

11. Flushing the Furnace. In order to remove adsorbed gases 
from the glass pot and the insulating materials, the following proce- 
dure was adopted. The furnace was assembled as shown in Fig. 3 
with the melting pot in place. The Gaede pump was started and the 
pressure in the furnace reduced to 0.02 mm. At the same time the 
current was started in the heating coil and the pot heated to a 
temperature several hundred degrees higher than that employed in 
the melting operation. The furnace was kept hot and the Gaede 



18 



ILLINOIS ENGINEERING EXPERIMENT STATION 



pump in operation for several hours. Pure nitrogen was then ad- 
mitted to the furnace chamber until atmospheric pressure was 
attained, after which the nitrogen was pumped out. This wash- 
ing with nitrogen was repeated several times and the furnace finally 
allowed to cool while filled with nitrogen. 

12. Melting the GlassWhen the nitrogen filled furnace was 
entirely cold, the water cooled dome was hoisted sufficiently to permit 
a weighed quantity (about 350 grams) of glass to be dropped into 
the melting pot, after which the dome was immediately lowered into 
place and the Gaede pump started. At the same time the resistor was 
heated to just below red heat, and after the pressure had fallen to 
0.02 mm. the furnace was again flushed two times with pure nitrogen. 

Finally, with a vacuum of 0.01 to 0.02 mm. in the furnace, it was 
sealed by closing a stop-cock, and the temperature of the pot was 
raised to about 1000 deg. C. and kept there for one hour. The pres- 
sure was then noted and the temperature of the pot allowed to drop 
to about 650 deg. C. after which pure nitrogen was admitted until 
atmospheric pressure had been reached. 

With the resistor maintained at about 650 deg. C. the contents 
of the furnace were then pumped out through the analysing train and 
the furnace washed out with nitrogen, the washings being also pumped 
out through the analysing* train. The furnace was finally allowed to 
stand full of pure nitrogen until time for the next experiment. 

13. The Results. The results obtained in four separate experi- 
ments, using pieces of the same block of glass, are shown in Table 1. 
It will be noticed that oxygen and carbon dioxide are present in solu- 
tion itf the glass to the extent of 0.1 per cent of its weight. Part, 
perhaps the greater part, of the carbon dioxide is present in the com- 
bined state as carbonate, and some of it would therefore be retained 
in the glass even under a vacuum of 0.02 mm. 

TABLE 1 

PER CENT BY WEIGHT OF OXYGEN AND OF CARBON 
DIOXIDE DISSOLVED IN A BARIUM-FLINT OPTICAL GLASS 



GAS 


WEIGHT PER CENT 


MOLES PER LITER 


1 


2 


3 


4 


Mean 


o a . 


0.078 
.017 


0.092 
.023 


0.074 
.031 


0.086 


0.08 
.02 


0.07 
0.01 


CO2 






FIG. 6. APPARATUS FOR MEASURING AND ANALYSING THE DISSOLVED GASES 

IN GLASS 



DISSOLVED GASES IN GLASS 21 



IV. A SPECIAL APPARATUS FOR BOTH MEASURING AND ANALYSING 
THE DISSOLVED GASES IN GLASS 

14. Description of the Apparatus. The experiments described 
in the preceding section gave satisfactory evidence of the existence 
of dissolved oxygen and carbon dioxide in considerable amounts in 
finished glass. The apparatus and the method employed in these ex- 
periments were, however, rather cumbersome and complicated, and it 
was very difficult to make sure that no leakage of atmospheric gases 
into the evacuated furnace took place. The method, moreover, did 
not yield a measure of the total amount of the dissolved gases. 

In order to eliminate these drawbacks a new vacuum furnace 
was designed, constructed entirely of glass and porcelain, which could 
readily be made perfectly gas tight, and which also permitted all of 
the gas evolved by the glass to be both measured and analysed. The 
final form of this apparatus is shown in Figs. 6 and 7. 

The vacuum casing of the furnace consisted of a pyrex glass 
tube 5 cm. in diameter and 13 cm. high, provided with a ground glass 
stopper having a mercury seal at the joint. The melting pot was a 
cylindrical porcelain tube, 3 cm. in diameter and 13 cm. high. It was 
wound with platinum wire and slipped into a tightly fitting porcelain 
protecting tube. An outer more loosely fitting protecting tube com- 
pleted this portion of the apparatus, which was suspended inside of 
the glass tube by means of two heavy copper leads which passed out 
through the capillary tubes, T and T 2 . The joint between these lead 
wires and the top of the capillary tubes was made tight by a rubber 
plug covered with a beeswax-rosin mixture. 

15. Determination of Free Volume of Furnace. For this pur- 
pose a calibrated 230 cu. cm. flask containing air at atmospheric 
pressure was attached at M and the stop-cock S was closed. The 
furnace, containing the melting pot and its protecting tubes, was then 
evacuated to a pressure of 0.1 mm. of mercury and, after the connec- 
tion to the pump had been closed, stop-cock S t was opened and the 
manometer reading again taken. The volume of the flask being 
known, and the change in pressure which occurred on connecting it 
to the evacuated apparatus, the free volume of the latter was calcu- 
lated to be 475 cu. cm. 



22 



ILLINOIS ENGINEERING EXPERIMENT STATION 



M&rcury Sea/ 
Ground Joint 



C/ay Protecting PoK 



a 14 Copper Wire 



o. /8 P/atinvm Wire 



a 25 Platinum W/re 




FIG. 7. DETAIL OF APPARATUS FOR MEASURING AND ANALYSING THE DISSOLVED 

GASES IN GLASS 



DISSOLVED GASES IN GLASS 23 

16. Experimental Procedure. The following procedure was em- 
ployed in measuring and analysing the dissolved gases in glass. A 
weighed sample of glass in some cases, 25 grams, in others, 50 
grams, was placed in the melting pot and the whole apparatus as- 
sembled as shown in the figure. With stop-cock S x closed, the ap- 
paratus was evacuated to a pressure of 0.1 mm. of mercury, and at 
the same time a sufficient current was passed through the heating 
wire to heat the pot and protecting tubes to about 400 deg. C., at 
which temperature no dissolved gas is given up by the glass.' This 
preliminary heating and evacuating was necessary in order to remove 
adsorbed moisture from the porcelain. The connection to the pump 
was then closed and the whole apparatus allowed to stand for several 
hours in order to make sure that it was perfectly tight, this fact, of 
course, being indicated by an absolutely constant manometer reading. 
Sufficient current was then passed through the heating coil to 
raise the temperature of the glass to 1400 deg. C. and the heating was 
continued till no more gas was evolved from the molten glass, as shown 
by a steady manometer reading. During this heating a blast of air 
was directed on the ground glass joint. The apparatus was then 
cooled to room temperature and the manometer reading was recorded. 
The free volume of the furnace being known, the total amount of gas 
evolved by the glass could be calculated. The total time required 
for a run was from two to three hours. 

After the final manometer reading had been taken, the stop-cock 
leading to the manometer was closed, the manometer disconnected, 
and a small Orsat apparatus connected in its place. The tube M was 
then connected to an adjustable mercury reservoir, the mercury filling 
the tube completely up to the stop-cock. This stop-cock was opened 
and the furnace completely filled with mercury, all of the gas being 
driven out ahead of the mercury into the Orsat apparatus, where it 
was analysed for carbon dioxide and oxygen, any residual gas being 
considered nitrogen. The accuracy of the chemical analysis was 
about one per cent. 



24 ILLINOIS ENGINEERING EXPERIMENT STATION 



V. THE GAS CONTENT OF THREE TYPES OF COMMERCIAL GLASS 

17. A Barium Flint Optical Glass. This was the same type of 
glass as that used in the experiments described in Chapter III, but 
was obtained from the Pittsburgh Plate Glass Company, and may 
have differed somewhat in composition. Its index of refraction was 
given by Dr. Hostetter as "about 1.605, and its v value, about 43.6.'* 

Two experiments on 50 gram portions, and one on a 25 gram 
portion, of one block of glass gave total volumes of dissolved gases 
(measured under standard conditions) of 15.6, 14.3 and 8.04 cu. cm. 
respectively. The average is 15.3 cu. cm. for 50 grams of glass, 
amounting to 1.1 times the volume of the glass itself. Two samples of 
another block of the glass gave a volume of gas (under standard con- 
ditions) equal to half the volume of the glass. The history of the 
two blocks used in these experiments is not known. They were taken 
from a 25 Ib. lot of cullet, and may have come from two entirely dif- 
ferent melts. It is, of course, to be expected that the gas content of 
finished glass will depend very materially upon the melting and fining 
procedure which has been followed. 

The gas from the second block of glass was analysed, and was 
found to consist of 25 per cent carbon dioxide and 75 per cent oxygen. 
If any nitrogen was present it was less than one per cent. 

18. A Light Flint Bulb Glass. The sample of glass used had the 
following composition according to the manufacturer's analysis: 

Oxide . . * . Si0 2 PbO A1 2 3 CaO Na 2 
Mole (per cent) 75.0 7.15 0.45 0.60 16.76 

Two melts of 50 grams each were made and they gave respectively 
3.2 and 3.5 cu. cm. of gas under standard conditions. The dissolved 
gas thus amounted to 0.2 times the volume of the glass itself. Analysis 
of the gas gave 58 per cent carbon dioxide, 24 per cent oxygen, and 
18 per cent nitrogen. The density of the glass was 2.89. 

19. A Borosilicate Laboratory Glass. The glass investigated had 
approximately the following composition: 

Oxide . . . Si0 2 B,0 3 As 2 5 A1 2 3 Fe 2 3 CaO MgONa 2 O K 2 
Mole(percent) 83.0 10.5 0,2 1,2 0.1 0.3 0,1 4,4 0.1 



DISSOLVED GASES IN GLASS 



25 



Twenty-five grams of glass gave, on melting, a volume of gas 
(under standard conditions) equal to 0.2 times the volume of the 
glass. On analysis the gas was found to consist of 26 per cent carbon 
dioxide, 37 per cent oxygen, and 37 per cent nitrogen. 



TABLE 2 
SUMMARY OF RESULTS ON THE AMOUNTS OF DISSOLVED GASES IN FINISHED GLASS 





VOLUME PER CENT S.T.P. 


WEIGHT PEB CENT 


CONCENTRATION 
MOLES PER LITER 


GLASS 


2 


CO 2 


N 2 


Total 


O fl 


CO 2 


N 2 


Total 


2 


CO 2 


N 2 


Barium flint .1 
Barium flint .2 
Light flint 
Borosilicate 


83 
36 
4.5 
6 


27 
12 
10 
5 


<1 
<1 
3 
6 


110 
48 
18 
17 


0.035 
.015 
.0045 
.0036 


0.011 
.0045 
.014 
.0035 


0!6025 
.0031 


0.046 
.020 
.021 
.010 


0.033 
.016 
.004 
.0028 


0.011 
.005 
.010 
.002 


6! 663 

.0028 


Water at deg. C . 


















.0023 


.080 


.0010 



20. Discussion of the Results. The results obtained with the 
above three varieties of glass are summarized in Table 2. Owing to 
lack of data concerning the melting schedule and finishing operation 
used in the melts from which the samples studied originated, it is 
impossible to correlate the results obtained with the manufacturing 
procedure. 

The quantity and nature of the gases present in the finished glass 
must obviously depend upon the batch composition and the melting 
and finishing procedures. The influence of the latter factor is prob- 
ably responsible for the different results obtained with the different 
samples of the barium flint optical. 

It is not probable that any appreciable quantities of gas are ab- 
sorbed by the glass from the atmosphere of the furnace, except possibly 
in the case of glasses which are mechanically stirred for a long period. 
This conclusion seems to be borne out by the absence of nitrogen from 
the barium flint glass. The dissolved gas must therefore originate 
from the gases given off by the batch itself during the melting and 
fining processes. 

At the end of the melting period, just before the fining operation 
begins, the glass usually contains numbers of small bubbles in which, 
owing to the high surface tension of molten glass, the gas is under 
a pressure greater than atmospheric. At the end of the fining opera- 



26 ILLINOIS ENGINEERING EXPERIMENT STATION 

tion the glass is therefore probably still somewhat supersaturated with 
gas, since, owing to its high viscosity, it cannot very rapidly give up 
this extra dissolved gas. The higher the finishing temperature, and 
the longer the glass is held at high temperatures, the smaller should 
be the amount of dissolved gas remaining in the finished glass. This 
conclusion seems to be borne out by the results obtained with the boro- 
silicate glass, which is a glass requiring very high finishing and work- 
ing temperatures. The great preponderance of acidic constituents in 
this glass may, however, be partially responsible for the small quantity 
of carbon dioxide found, since as shown by Niggli,* a good part of 
the dissolved carbon dioxide in glass is probably combined with the 
basic constituents. 



* Niggli, Paul, "The Phenomena of Equilibria between Silica and the Alkali Carbonates," 
Jour. Araer. Chem. Soc., Vol. 35, 1706 (1913), 



DISSOLVED GASES IN GLASS 27 



VI. THE SIGNIFICANCE OF DISSOLVED GASES IN GLASS 

21. The Relation between Adsorbed and Dissolved Gas. It has 
long been recognized that glass in'common with many other substances 
displays a strong tendency to adsorb, that is, to condense upon its 
surface, gases with which it is in contact.* 

Adsorption may indeed be regarded as a type of solution in which 
the dissolved molecules do not penetrate below the surface layer of 
the adsorbent. Such a " surf ace solution" will therefore ordinarily 
be saturated when the surface of the adsorbent is covered with a layer 
of the adsorbed material one molecule deep and with its molecules 
close-packed laterally, t 

Adsorption may sometimes be accompanied by a gradual penetra- 
tion of the adsorbed material beneath the surface layer of the ad- 
sorbent, that is, it may be accompanied by ordinary or " volume " solu- 
tion; but in the case of glass at low temperatures, such solution will 
probably be confined to the superficial layers. Adsorbed or superfici- 
ally dissolved gases are thus to be distinguished from the dissolved 
gases studied in the present investigation, which are more or less 
uniformly disseminated throughout the whole mass of the glass. Lang- 
muirj has found that water vapor is adsorbed and then slowly dis- 
solved by glass. He also found that lamp bulbs when heated in vacuo 
evolved adsorbed carbon dioxide and nitrogen in addition to water 
vapor. 

Recently Sherwood has devised a dynamic method for studying 
the gases evolved by glass when heated in vacuo to temperatures be- 
low its softening point. He found that adsorbed gases could be re- 
moved completely by heating to 200 deg. C. in vacuo and that the 
amount of such gases corresponded to a layer about one molecule 



* Of. Guichard, M., "Sur les gaz degage des parois des tubes de verre." Bull. Soc. 
Chim. 100, 440 (1911). 

t For a more detailed discussion of the relation between adsorption and solution see 
Washburn, E. W., "Introduction to the Principles of Physical Chemistry," Ed. 2, Chap. XXV, 
The McGraw-Hill Book Company, New York, 1921. 

$ Langmuir, I.. "The Adsorption of Gases on Plane Surface's of Glass. Mica and 
Platinum," Jour. Amer. Chem. Soc., Vol. 38, 2283-4 (1916); Ibid., Vol. 40, 1387 (1918). 

Sherwood, R. G., "Gases and Vapors from Glass," Phys. Rev., Vol. 12, 448 (1918). 



28 ILLINOIS ENGINEERING EXPERIMENT STATION 

deep over the surface of the glass. On subsequent heating to 500 deg. 
C. a further evolution of gas occurred, which he attributed to " chem- 
ical reactions " occurring within the glass. 

The well known jump in pressure within an exhausted glass 
vessel which occurs when it is " sealed off" and the subsequent deteri- 
oration of the vacuum with time has been studied by Shrader.* He 
concludes that : ' ' The vacuum in sealed vessels deteriorates with time, 
rapidly at first, and then more slowly, and subsequent heating, even 
at temperatures lower than the heat-treating temperature, results in 
increase of pressure due to further liberation of the gases and vapors 
from the glass. No connection between different samples of the same 
glass or different glasses can be established. It is quite probable that 
there are variations in the properties of different samples of the same 
glass quite as great as the variations between different glasses of about 
the same grade. ' ' 

There is every reason to believe that the dissolved gases in glass 
play an important role in the behavior described by Shrader. Cer- 
tainly the jump in pressure which occurs during the sealing-off 
process can be ascribed to this source, and it seems entirely probable 
that gas-free glass would be superior in many respects to ordinary 
glass for the manufacture of high vacuum apparatus. 

The adsorption of various gases by glass and their subsequent 
evolution with vacuum-heat treatment have been studied, particularly 
with respect to the production and maintenance of high vacua, by 
Ulreyt in a recent investigation which at the time of writing is avail- 
able only in abstract. His conclusions in the main substantiate those 
already referred to, but the following may be mentioned : 

(1) "Glass from which practically all absorbed gases 
have been removed by melting in vacuo subsequently reab- 
sorbed gases from the atmosphere at room temperature." 

(2) "At temperatures up to the softening point, diffusion 
of gases of the atmosphere through glass does not take place." 
With reference to his first conclusion, a distinction should be 

drawn between absorbed or dissolved gases and adsorbed gases. The 
removal of the former by melting in vacuo does not, of course, affect 



* Shrader, J. E., "Residual Gases and Vapors in Glass Bulbs," Phys. Rev., Vol. 13, 437 
(1919). 

t Ulrey, D., "Evolution and Absorption of Gases by Glass," Abstract in Phys. Rev,, Vol. 
14, 160 (1919). 



DISSOLVED GASES IN GLASS 29 

the ability of the glass to adsorb gases from the atmosphere, the latter 
being an entirely independent process. 

The evidence for his second conclusion not being available, its 
exact significance is not entirely clear. The fact that the atmospheric 
gases seem able to diffuse througji quartz glass at comparatively low 
temperatures renders it not improbable* that a similar behavior might 
be exhibited by some of the ordinary commercial glasses under some 
circumstances, although doubtless to a considerably less extent. 

22. The Influence of Dissolved Gases upon the Properties and 
Behavior of Glass. Evolution of dissolved gas in the form of bubbles 
tends to occur whenever the pressure, on glass, while in a fluid condi- 
tion, is decreased. Such a decrease in pressure will occur during the 
manufacturing operation whenever there is a marked fall in the 
barometer, and it would be interesting to know whether there is any 
record of troubles with "seedy" glass accompanying periods of 
barometric depression. 

A condition of reduced pressure with a consequent evolution of 
bubbles of gas also results from the strains set up by the contraction 
of the glass itself. If the outside of a mass of glass be allowed to 
solidify while the interior is still in a fluid condition, it is evident 
that the gradual solidification of the remaining glass must bring about 
a tension upon the still fluid portions; and this decrease in pressure 
will cause them to evolve their dissolved gases, with the consequent 
formation of a mass of bubbles in those portions of the glass which 
remain longest in the fluid condition. Some interesting examples 
of the formation of seed from this cause have been described by 
Williams, t 

Still another instance of the occurrence of reduced pressure dur- 
ing manufacturing operations is met with in cases where the glass is 
"gathered" by suction, as in the case of the Owens machine. If the 
glass when it reaches the gathering machine is supersaturated with 
dissolved gases, the operation of gathering will evidently result in 
the formation of seed, some of which will not disappear again when 
the suction is released. If the glass at the moment of gathering is 



* Of. Le Chatelier, "La Silice et les Silicates," p. 94, Hermann et Fils, Paris 1914; 
Mayer, E. C., "Leakage of Gases through Quartz Tubes," Phys. Rev., Vol. 4, 283 (1915), 

t Williams, A. E., "Observations on the Formation of Seed in Optical Glass Melts," 
Jour. Amer. Ceramic Soc., Vol. I, 134 (1918). 



30 ILLINOIS ENGINEERING EXPERIMENT STATION 

undersaturated with the dissolved gases, as will be the case if it has 
been kept long enough at a sufficiently high temperature before reach- 
ing the gathering machine, the suction may still result in the momen- 
tary appearance of seeds, but these will be largely of the vacuum type 
and not permanent; if permanent, they will probably be exceed- 
ingly small, after the glass is finished. 

Since both the appearance and disappearance of the seeds under 
these conditions is a process requiring a certain amount of time for 
the attainment of equilibrium, the viscosity of the glass, the time 
during which it is under the reduced pressure, and the subsequent 
cooling and annealing operations will evidently all have an influence 
on the final state of the glass as regards freedom from seeds. Seeds 
formed from glass which is supersaturated or practically completely 
saturated with dissolved gases cannot be removed by annealing, but 
seeds resulting from reduced pressure upon glass which is under- 
saturated with dissolved gases will disappear or be greatly reduced in 
size by proper annealing. 

The complete story of the effect of dissolved gases upon the prop- 
erties and behavior of glass must await the results of further in- 
vestigation. It seems entirely probable that the presence of dissolved 
gases, and especially of microscopic seeds, may materially increase 
the tendency of the glass to devitrify, and the entire removal of this 
constituent might make it possible to obtain results which are not 
possible under ordinary conditions owing to the rapidity of devitrifica- 
tion. Certainly the known facts concerning the behavior of other 
supercooled solutions point in this direction.* 

23. The Use of Vacuum Furnaces in the Manufacture of Glass. 
The results described in the preceding pages are to be regarded as 
preliminary only. It is intended to continue the investigation not 
only for the purpose of determining the influence of dissolved gases 
upon the properties and behavior of glass, but also for the purpose of 
determining the practicability and value of a commercial process for 
the production of gas free glass. 

The investigation of this subject was started early in 1918, and 
the results thus far attained indicate that a vacuum furnace process 
for the manufacture of certain types of glass is entirely feasible on 



* In this connection see Germann, A. F. O., "The Devitrification of Glass, a Surface 
Phenomenon. The Repair of Crystallized Glass Apparatus." Jour. Amer. Chem. Soc., Vol. 43, 
11 (1921). 



DISSOLVED GASES IN GLASS 31 

an industrial scale, and that it offers a number of pronounced ad- 
vantages over current methods. It eliminates entirely the fining 
operation as ordinarily understood, materially reduces the high finish- 
ing temperatures required with some glasses, produces in all cases a 
product absolutely free from even the smallest seeds, and these re- 
sults suggest the possibility of considerably increasing the yield of 
perfect glass. Its main field of usefulness will probably be in the 
manufacture of certain types of optical glasses and of glass for high 
vacuum apparatus. 



32 ILLINOIS ENGINEERING EXPERIMENT STATION 



VII. SUMMARY 

24. Summary of Results. The results of the investigation to date 
may be summarized as follows: 

(1) All varieties of glass in the finished state contain dis- 
solved gases. 

(2) The amount of this dissolved gas is sufficient to cause 
the glass to effervesce violently if the pressure upon it be sud- 
denly reduced while it is in a fluid condition. 

(3) The amount and composition of the dissolved gas 
varies greatly with the type of glass and the detail of the 
melting and fining procedures. 

(4) In the three types of industrial glass examined, the 
volume of the dissolved gases (measured under standard con- 
ditions) varied from 0.2 to 2 times the volume of the glass it- 
self. 

(5) Carbon dioxide, oxygen, and nitrogen were found in 
varying amounts in the gas. 

In addition, as a result of this experimental work, a convenient 
apparatus for measuring and analysing the dissolved gases was de- 
veloped, and an improved type of vacuum furnace for the manufac- 
ture of gas-free glass was constructed. 



LIST OF 
PUBLICATIONS OF THE ENGINEEBING EXPERIMENT STATION 



Bulletin No. 1. Tests of Reinforced Concrete Beams, by Arthur N. Talbot. 
1904. None available. 

Circular No. 1. High-Speed Tool Steels, by L. P. Breckenridge. 1905. None 
available. 

Bulletin No. 2. Tests of High-Speed Tool Steels on Cast Iron, by L. P. 
Breckenridge and Henry B. Dirks. 1905. None available. 

Circular No. 2. Drainage of Earth Roads, by Ira O. Baker. 1906. None 
available. 

Circular No. 3. Fuel Tests with Illinois Coal (Compiled from tests made 
by the Technological Branch of the U. S. G. S., at the St. Louis, Mo., Fuel Test- 
ing Plant, 1904-1907), by L. P. Breckenridge and Paul Diserens. 1908. Thirty 
cents. 

Bulletin No. S. The Engineering Experiment Station of the University of 
Illinois, by L. P. Breckenridge. 1906. None available. 

Bulletin No. 4. Tests of Reinforced Concrete Beams, Series of 1905, by 
Arthur N. Talbot. 1906. Forty-five cents. 

Bulletin No. 5. Resistance of Tubes to Collapse, by Albert P. Carman and 
M. L. Carr. 1906. None available. 

Bulletin No. 6. Holding Power of Railroad Spikes, by Roy I. Webber. 1906. 
None available. 

Bulletin No. 7. Fuel Tests with Illinois Coals, by L. P. Breckenridge, S. W. 
Parr, and Henry B. Dirks. 1906. None available. 

Bulletin No. 8. Tests of Concrete: I, Shear; II, Bond, by Arthur N. Tal- 
bot. 1906. None available. 

Bulletin No. 9. An Extension of the Dewey Decimal System of Classification 
Applied to the Engineering Industries, by L. P. Breckenridge and G. A. Good- 
enough. 1906. Revised Edition, 1912. Fifty cents. 

Bulletin No. 10. Tests of Concrete and Reinforced Concrete Columns, Series 
of 1906, by Arthur N. Talbot. 1907. None available. 

Bulletin No. 11. The Effect of Scale on the Transmission of Heat through 
Locomotive Boiler Tubes, by Edward C. Schmidt and John M. Snodgrass. 1907. 
None available. 

Bulletin No. U. Tests of Reinforced Concrete T-Beams, Series of 1906, by 
Arthur N. Talbot. 1907. None available. 

Bulletin No. IS. An Extension of the Dewey Decimal System of Classifica 
tion Applied to Architecture and Building, by N. Clifford Ricker. 1907. None 
available. 

Bulletin No. 14. Tests of Reinforced Concrete Beams, Series of 1906, by 
Arthur N. Talbot. 1907. None available. 

33 



34 PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 

Bulletin No. 15. How to Burn Illinois Coal without Smoke, by L. P. Breek- 
enridge. 1907. None available. 

Bulletin No. 16. A Study of Roof Trusses, by N. Clifford Bicker. 1907. 
None available. 

Bulletin No. 17. The Weathering of Coal, by S. W. Parr, N. D. Hamilton, 
and W. F. Wheeler. 1907. None available. 

Bulletin No. 18. The Strength of Chain Links, by G. A. Goodenough and 
L. E. Moore. 1907. Forty cents. 

Bulletin No. 19. Comparative Tests of Carbon, Metallized Carbon, and Tan- 
talum Filament Lamps, by T. H. Amrine. 1907. None available. 

Bulletin No. SO. Tests of Concrete and Reinforced Concrete Columns, Series 
of 1907, by Arthur N. Talbot. 1907. None available. 

Bulletin No. SI. Tests of a Liquid Air Plant, by C. S. Hudson and C. M. Gar- 
land. 1908. Fifteen cents. 

Bulletin No. 28. Tests of Cast-Iron and Reinforced Concrete Culvert Pipe, 
by Arthur N. Talbot. 1908. None available. 

Bulletin No. 83. Voids, Settlement, and Weight of Crushed Stone, by Ira O. 
Baker. 1908. Fifteen cents. 

*Bulletin No. 24. The Modification of Illinois Coal by Low Temperature Dis- 
tillation, by S. W. Parr and C. K. Francis. 1908. Thirty cents. 

Bulletin No. 85. Lighting Country Homes by Private Electric Plants, by 
T. H. Amrine. 1908. Twenty cents. 

Bulletin No. 26. High Steam-Pressure in Locomotive Service. A Review of a 
Report to the Carnegie Institution of Washington, by W. F. M. Goss. 1908. 
Twenty-five cents. 

Bulletin No. 87. Tests of Brick Columns and Terra Cotta Block Columns, by 
Arthur N. Talbot and Duff A. Abrams. 1908. Twenty-five cents. 

Bulletin No. 88. A Test of Three Large Reinforced Concrete Beams, by 
Arthur N. Talbot. 1908. Fifteen cents. 

Bulletin No. 89. Tests of Reinforced Concrete Beams: Resistance to Web 
Stresses, Series of 1907 and 1908, by Arthur N. Talbot. 1909. Forty-five cents. 

Bulletin No. SO. On the Rate of Formation of Carbon Monoxide in Gas Pro- 
ducers, by J. K. Clement, L. H. Adams, and C. N. Haskins. 1909. Twenty-five 
cents. 

Bulletin No. SI. Tests with House-Heating Boilers, by J. M. Snodgrass. 1909. 
Fifty-five cents. 

Bulletin No. S2. The Occluded Gases in Coal, by S. W. Parr and Perry 
Barker. 1909. Fifteen cents. 

Bulletin No. S3. Tests of Tungsten Lamps, by T. H. Amrine and A. Guell. 
1909. Twenty cents. 

*Bulletin No. 34. Tests of Two Types of Tile-Roof Furnaces under a Water 
Tube Boiler, by J. M. Snodgrass. 1909. Fifteen cents. 



'A limited number of copies of bulletins starred are available for free distribution 



PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 35 

Bulletin No. 85. A Study of Base and Bearing Plates for Columns and 
Beams, by N. Clifford Bicker. 1909. Twenty cents. 

Bulletin No. 36. The Thermal Conductivity of Fire-Clay at High Temper- 
atures, by J. K. Clement and W. L. Egy. 1909. Twenty cents. 

Bulletin No. 37. Unit Coal and the Composition of Coal Ash, by S. W. Parr 
and W. F. Wheeler. 1909. None available. 

Bulletin No. 38. The Weathering of Coal, by S. W. Parr and W. F. Wheeler. 
1909. Twenty-five cents. 

* Bulletin No. 39. Tests of Washed Grades of Illinois Coal, by C. S. McGovney. 
1909. Seventy -five cents. 

Bulletin No. 40. A Study in Heat Transmission, by J. K. Clement and C. M. 
Garland. 1909. Ten cents. 

Bulletin No. 41. Tests of Timber Beams, by Arthur N. Talbot. 1909. Thirty- 
five cents. 

*Bulletin No. 42. The Effect of Keyways on the Strength of Shafts, by Her- 
bert F. Moore. 1909. Ten cents. 

Bulletin No. 43. Freight Train Resistance; by Edward C. Schmidt. 1910. 
Seventy-five cents. 

Bulletin No. 44. An Investigation of Built-up Columns under Load, by 
Arthur N. Talbot and Herbert F. Moore. 1910. Thirty-five cents. 

*Bulletin No. 45. The Strength of Oxyacetylene Welds in Steel, by Herbert 
L. Whittemore. 1910. Thirty-five cents. 

Bulletin No. 46. The Spontaneous Combustion of Coal, by S. W. Parr and 
F. W. Kressman. 1910. Forty-five cents. 

*Bulletin No. 47. Magnetic Properties of Heusler Alloys, by Edward B. 
Stephenson. 1910. Twenty-five cents. 

*Bulletin No. 48. Resistance to Flow through Locomotive Water Columns, by 
Arthur N. Talbot and Melvin L. Enger. 1911. Forty cents. 

*Bulletin No. 49. Tests of Nickel-Steel Riveted Joints, by Arthur N. Talbot 
and Herbert F. Moore. 1911. Thirty cents. 

*Bulletin No. 50. Tests of a Suction Gas Producer, by C. M. Garland and 
A. P. Kratz. 1911. Fifty cents. 

Bulletin No. 51. Street Lighting, by J. M. Bryant and H. G. Hake. 1911. 
Thirty-five cents. 

*Bulletin No. 52. An Investigation of the Strength of Rolled Zinc, by Herbert 
F. Moore. 1911. Fifteen cents. 

*Bulletin No. 53. Inductance of Coils, by Morgan Brooks and H. M. Turner. 
1912. Forty cents. 

Bulletin No. 54. Mechanical Stresses in Transmission Lines, by A. Guell. 
1912. Twenty cents. 

*Bulletin No. 55. Starting Currents of Transformers, with Special Reference 
to Transformers with Silicon Steel Cores, by Trygve D. Yensen. 1912. Twenty 
cents. 



*A limited number of copies of bulletins starred are available for free distribution. 



36 PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 

* Bulletin No. 56. Tests of Columns: An Investigation of the Value of Con- 
crete as Eeinforcement for Structural Steel Columns, by Arthur N. Talbot and 
Arthur E. Lord. 1912. Twenty-five cents. 

* Bulletin No. 57. Superheated Steam in Locomotive Service. A Review of 
Publication No. 127 of the Carnegie Institution of Washington, by W. F. M 
Goss. 1912. Forty cents. 

*Bulletin No. 58. A New Analysis of the Cylinder Performance of Reciprocat- 
ing Engines, by J. Paul Clayton. 1912. Sixty cents. 

*Bulletin No. 59. The Effect of Cold Weather upon Train Resistance and 

Tonnage Rating, by Edward C. Schmidt and F. W. Marquis. 1912. Twenty cents. 

Bulletin No. 60. The Coking of Coal at Low Temperature, with a Preliminary 

Study of the By-Products, by S. W. Parr and H. L. Olin. 1912. Twenty-five cents. 

* Bulletin No. 61. Characteristics and Limitation of the Series Transformer, 
by A. R. Anderson and H. R. Woodrow. 1912. Twenty-five cents. 

Bulletin No. 62. The Electron Theory of Magnetism, by Elmer H. Williams. 

1912. Thirty-five cents. 

Bulletin No. 63. Entropy-Temperature and Transmission Diagrams for Air, 
by C. R. Richards. 1913. Twenty-five cents. 

*Bulletin No. 64. Tests of Reinforced Concrete Buildings under Load, by 
Arthur N. Talbot and Willis A. Slater. 1913. Fifty cents. 

*Bulletin No. 65. The Steam Consumption of Locomotive Engines from the 
Indicator Diagrams, by J. Paul Clayton. 1913. Forty cents. 

Bulletin No. 66. The Properties of Saturated and Superheated Ammonia 
Vapor, by G. A. Goodenough and William Earl Mosher. 1913. Fifty cents. 

Bulletin No. 67. Reinforced Concrete Wall Footings and Column Footings, 
by Arthur N. Talbot. 1913. None available. 

Bulletin No. 68. The Strength of I-Beams in Flexure, by Herbert F. Moore. 

1913. Twenty cents. 

Bulletin No. 69. Coal Washing in Illinois, by F. C. Lincoln. 1913. Fifty 
cents. 

Bulletin No. 70. The Mortar-Making Qualities of Illinois Sands, by C. C. 
Wiley. 1913. Twenty cents. 

Bulletin No. 71. Tests of Bond between Concrete and Steel, by Duff A. 
Abrams. 1913. One dollar. 

*Bulletin No. 72. Magnetic and Other Properties of Electrolytic Iron Melted 
in Vacuo, by Trygve D. Yensen. 1914. Forty cents. 

Bulletin No. IS. Acoustics of Auditoriums, by F. R. Watson. 1914. Twenty 
cents. 

*Bulletin No. 74. The Tractive Resistance of a 28-Ton Electric Car, by Harold 
H. Dunn. 1914. Twenty-five cents. 

Bulletin No. 75. Thermal Properties of Steam, by G. A. Goodenough. 1914. 
Thirty-five cents. 



*A limited number of copies of bulletins starred are available for free distribution. 



PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 37 

Bulletin No. 76. The Analysis of Coal with Phenol as a Solvent, by S. W. 
Parr and H. F. Hadley. 1914. Twenty-five cents. 

"Bulletin No. 77. The Effect of Boron upon the Magnetic and Other Prop- 
erties of Electrolytic Iron Melted in Vacuo, by Trygve D. Yensen. 1915. Ten 
cents. 

Bulletin No. 78. A Study of Boiler, Losses, by A. P. Kratz. 1915. Thirty- 
five cents. 

"Bulletin No. 79. The Coking of Coal at Low Temperatures, with Special Bef- 
erence to the Properties and Composition of the Products, by S. W. Parr and 
H. L. Olin. 1915. Twenty-five cents. 

Bulletin No. 80. Wind Stresses in the Steel Frames of Office Buildings, by 
W. M. Wilson and G. A. Maney. 1915. Fifty cents. 

Bulletin No. 81. Influence of Temperature on the Strength of Concrete, by 
A. B. McDaniel. 1915. Fifteen cents. 

Bulletin No. 82. Laboratory Tests of a Consolidation Locomotive, by E. C. 
Schmidt, J. M. Snodgrass, and B. B. Keller. 1915. Sixty-five cents. 

"Bulletin No. 83. Magnetic and Other Properties of Iron-Silicon Alloys, 
Melted in Vacuo, by Trygve D. Tensen. 1915. Thirty-five cents. 

Bulletin No. 84. Tests of Beinforced Concrete Flat Slab Structures, by 
Arthur N. Talbot and W. A. Slater. 1916. Sixty-five cents. 

"Bulletin No. 85. The Strength and Stiffness of Steel under Biaxial Loading, 
by A. J. Becker. 1916. Thirty-five cents. 

Bulletin No. 86. The Strength of I-Beams and Girders, by Herbert F. Moore 
and W. M. Wilson. 1916. Thirty cents. 

"Bulletin No. 87. Correction of Echoes in the Auditorium, University of Illi- 
nois, by F. B. Watson and J. M. White. 1916. Fifteen cents. 

Bulletin No. 88. Dry Preparation of Bituminous Coal at Illinois Mines, by 
E. A. Holbrook. 1916. Seventy cents. 

Bulletin No. 89. Specific Gravity Studies of Illinois Coal, by Merle L. Nebel. 
1916. Thirty cents. 

^Bulletin No. 90. Some Graphical Solutions of Electric Bailway Problems, by 
A. M. Buck. 1916. Twenty cents. 

Bulletin No. 91. Subsidence Besulting from Mining, by L. E. Young and 
H. H. Stoek. 1916. None available. 

"Bulletin No. 92. The Tractive Besistance on Curves of a 28-Ton Electric 
Car, by E. C. Schmidt and H. H. Dunn. 1916. Twenty-five cents. 

* Bulletin No. 93. A Preliminary Study of the Alloys of Chromium, Copper, 
and Nickel, by D. F. McFarland and O. E. Harder. 1916. Thirty cents. 

"Bulletin No. 94. The Embrittling Action of Sodium Hydroxide on Soft Steel, 
by S. W. Parr. 1917. Thirty cents. 

"Bulletin No. 95. Magnetic and Other Properties of Iron-Aluminum Alloys 
Melted in Vacuo, by T. D. Yensen and W. A. Gatward. 1917. Twenty-five cents 



limited number of copies of bulletins starred are available for free distribution. 



38 PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 

Bulletin No. 96. The Effect of Mouthpieces on the Flow of Water through 
a Submerged Short Pipe, by Fred B Seely. 1917. Twenty-five cents. 

Bulletin No. 97. Effects of Storage upon the Properties of Coal, by S. W. 
Parr. 1917. Twenty cents. 

Bulletin No. 98. Tests of Oxyacetylene Welded Joints in Steel Plates, by 
Herbert F. Moore. 1917. Ten cents. 

Circular No. 4. The Economical Purchase and Use of Coal for Heating 
Homes, with Special Reference to Conditions in Illinois. 1917. Ten cents. 

Bulletin No. 99. The Collapse of Short Thin Tubes, by A. P. Carman, 1917. 
Twenty cents. 

Circular No. 5. The Utilization of Pyrite Occurring in Illinois Bituminous 
Coal, by E. A. Holbrook. 1917. Twenty cents. 

Bulletin No. 100. Percentage of Extraction of Bituminous Coal with Special 
Reference to Illinois Conditions, by C. M. Young. 1917. 

Bulletin No. 101. Comparative Tests of Six Sizes of Illinois Coal on a Mi- 
kado Locomotive, by E. C. Schmidt, J. M. Snodgrass, and O. S. Beyer, Jr. 1917. 
Fifty cents. 

Bulletin No. 108. A Study of the Heat Transmission of Building Materials, 
by A. C. Willard and L. C. Lichty. 1917. Twenty-five cents. 

Bulletin No. 103. An Investigation of Twist Drills, by B. Benedict and W. 
P. Lukens. 1917. Sixty cents. 

Bulletin No. 104. Tests to Determine the Rigidity of Riveted Joints of Steel 
Structures, by W. M. Wilson and H. F. Moore. 1917. Twenty-five cents. 

Circular No. 6. The Storage of Bituminous Coal, by H. H. Stock. 1918. 
Forty cents. 

Circular No. 7. Fuel Economy in the Operation of Hand Fired Power 
Plants. 1918. Twenty cents. 

Bulletin No. 105. Hydraulic Experiments with Valves, Orifices, Hose, Nozzles, 
and Orifice Buckets, by Arthur N. Talbot, Fred B Seely, Virgil R. Fleming, and 
Melvin L. Enger. 1918. Thirty-five cents. 

Bulletin No. 106. Test of a Flat Slab Floor of the Western Newspaper Union 
Building, by Arthur N. Talbot and Harrison F. Gonnerman. 1918. Twenty cents. 
Circular No. 8. The Economical Use of Coal in Railway Locomotives. 1918. 
Twenty cents. 

Bulletin No. 107. Analysis and Tests of Rigidly Connected Reinforced Con- 
crete Frames, by Mikishi Abe. 1918. Fifty cents. 

Bulletin No. 108. Analysis of Statically Indeterminate Structures by the 
Slope Deflection Method, by W. M. Wilson, F. E. Richart, and Camillo Weiss. 
1918. One dollar. 

Bulletin No. 109. The Pipe Orifice as a Means of Measuring Flow of Water 
through a Pipe, by R. E. Davis and H. H. Jordan , 1918. Twenty-five cents. 

Bulletin No. 110. Passenger Train Resistance, by E. C. Schmidt rnd H. H. 
Dunn. 1918. Twenty cents. 

*A limited number of copies of bulletins starred are available) for free distribution. 



PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION 39 

* Bulletin No. 111. A Study of the Forms in which Sulphur Occurs in Coal, by 
A. R. Powell with S. W. Parr. 1919. Thirty cents. 

"Bulletin No. 112. Eeport of Progress in Warm-Air Furnace Research, by 
A. C. Willard. 1919. Thirty-five cents. 

*Bulletin No. US. Panel System of Coal Mining. A Graphical Study of Per- 
centage of Extraction, by C. M. Young.. 1919. 

*Bulletin No. 114. Corona Discharge, by Earle H. Warner with Jakob Kunz. 

1919. Seventy-five cents. 

"Bulletin No. 115. The Relation between the Elastic Strengths of Steel in 
Tension, Compression, and Shear, by F. B Seely and W. J. Putnam. 1920. Twenty 
cents. 

Bulletin No. 116. Bituminous Coal Storage Practice, by H. H. Stoek, C. W. 
Hippard, and W. D. Langtry. 1920. Ninety cents. 

"Bulletin No. 117. Emissivity of Heat from Various Surfaces, by V. S. Day. 

1920. Twenty cents. 

"Bulletin No. 118. Dissolved Gases in Glass, by E. W. Washburn, F. F. Footitt, 
and E. N. Bunting. 1920. Twenty cents. 



*A limited number of copies of bulletins starred are available for free distribution. 



THE UNIVERSITY OF ILLINOIS 
THE STATE UNIVERSITY 

Urbana 
DAVID KINLEY, Ph.D., LL.D., President 



THE UNIVERSITY INCLUDES THE FOLLOWING DEPARTMENTS 

The Graduate School 

The College of Liberal Arts and Sciences (Ancient and Modern Languages and 
Literatures; History, Economies, Political Science, Sociology; Philosophy, 
Psychology, Education; Mathematics; Astronomy; Geology; Physics; Chem- 
istry; Botany; Zoology, Entomology; Physiology; Art and Design) 

The College of Commerce and Business Administration (General Business, Bank- 
ing, Insurance, Accountancy, Railway Administration, Foreign Commerce; 
Courses for Commercial Teachers and Commercial and Civic Secretaries) 

The College of Engineering (Architecture; Architectural, Ceramic, Civil, Electrical, 
Mechanical, Mining, Municipal and Sanitary, and Railway Engineering; 
General Engineering Physics) 

The College of Agriculture (Agronomy; Animal Husbandry; Dairy Husbandry; 
Horticulture and Landscape Gardening; Agricultural Extension; Teachers' 
Course; Home Economics) 

The College of Law (Three-year and four-year curriculums based on two years and 
one year of college work respectively) 

The College of Education (including the Bureau of Educational Research) 

The Curriculum in Journalism 

The Curriculums in Chemistry and Chemical Engineering 

The School of Railway Engineering and Administration 

The School of Music (four-year curriculum) 

The Library School (two-year curriculum for college graduates) 

The College of Medicine (in Chicago) 

The College of Dentistry (in Chicago) 

The School of Pharmacy (in Chicago, Ph.G. and Ph.C. curriculums) 

The Summer Session (eight weeks) 

Experiment Stations and Scientific Bureau: U. S. Agricultural Experiment Sta- 
tion; Engineering Experiment Station; State Laboratory of Natural History; 
State Entomologist's Office; Biological Experiment Station on Illinois River; 
State Water Survey; State Geological Survey; U. S. Bureau of Mines Experi- 
ment Station. 

The library collections contain (July 1, 1920) 474,488 volumes and 111,474 
pamphlets. 

For catalogs and information address 

THE REGISTRAR 

Urbana, Illinois 



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University of Californh 

Berkeley