T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
July, 1918
time these valves were opened and air samples taken. These samples were taken in such a way as t o accurately represent the air behind the battery, or in other words, the air from the fire zone. The carbon monoxide was determined by the iodine pentoxide method, more t h a n one liter of air being passed over the heated iodine pentoxide in each determination. The results given in Tables I and z seem t o need no further explanation. The mine fire zone was partially opened in August 1917, and no further air samples were tested. TABLE 1-~TH LEVEL, GANGWAY BATTERY Oxygen DATE 01) SAMPLING Per cent 18.00 Dec. 1, 1916.. . 16.40 Dec. 5 . . . . . . . . Dec. 12.. . . . . . . . . . 15.80 Dec. 19.. . . . . . . . . . 16.00 Dec. 2 6 . , . . . . . . . . . 15.66 14.00 Jan. 5, 1917.. Jan. 1 1 . . . . . . . . . . . . 14.30 Jan. 18. . . . . . . . . . . . 13.60 Jan. 25 . . . . . . . . . . . . 14.20 F e b . 9 . . . . . . . . . . . . 13.00 Feb. 22 . . . . . . . . . . . 14.20 Mar. 8 . . . . . . . . . . . . 13.80 Mar. 22. . . . . . . . . . 13.90 Apr. 5 . . . . . . . . . . . . 12.42 Apr. 1 8 . . . . . . . . . . . 13.11 13.10 May 3.. 10.20 Mav 17.. M a + 31. . . . . . . . . . 9 . 9 0 June 14 . . . . . . . . . . . 8 . 7 0 June 2 8 . . . . . . . . . . . 9.00 July 1 2 . . . . . . . . . . . 6.40 July 2 6 . . . . . . . . . . . 4 . 8 0
.....
.......... .........
TABLE2-7T13 Oxygen SAMPLING Per cent Dec. 1, 1916.. . . . . . 13.63 Dec. 5 . . . . . . . . . . . . 12.00 Dec. 12. . . . . . . . . . . 11.51 14.10 Dec. 19 Dec. 2 6 . . . . . . . . . . . 1 3 . 7 8 Jan. 5, 1917.. . . . . . 9 . 8 0 Jan. 11 . . . . . . . . . . . . 10.80 Jan. 18. . . . . . . . . . . . 10.20 Jan. 25.. ........... 1 0 . 7 3 Feb. 9 . . . . . . . . . . . . 9 . 4 0 Feb. 22 . . . . . . . . . . . 11.10 Mar. 8 . . . . . . . . . . . . 10.00 Mar. 22. . . . . . . . . . 11.40 Apr. 5 . . . . . . . . . . . . 9 . 1 0 Apr. 1 8 . . . . . . . . . . . 10.20 M a y 3 . . . . . . . . . . . . 10.00 M a y 1 7 . . . . . . . . . . . 7.30 M a y 3 1 . . . . . . . . . . . 7.80 3.30 lune 1 4 . . .. June 2 8 . . . . . . . . . . . 3.20 July 12.. . . . . . . . . . 3.30 2.80 July 2 6 . . D A T E OF
...........
.........
1 Foster
Carbon Dioxide Per cent 0.99 1.16 1.34 1.61 1.69 1.71 2.11 2.48 2.38 3.04 2.31 2.38 1.60 2.43 2.34 2.67 3.20 2.22 3.42 3.32 4.21 4.47
Carbon Carbon Dioxide in Monoxide Methane Black Damp' Per cent Per cent Per cent 0.008 2.40 8.28 0.0057 2.33 5.85 0.0034 4.27 6.47 0.015 3.28 7.80 0.01 3.66 7.72 .... 4.46 5.87 0,006 4.51 7.66 0.004 5.72 8.36 0.002 8.41 4.22 0.002 9.20 5.16 0.005 8.13 4.12 0.001 7.78 0.0016 3.87 5.23 3.55 None 6.62 4.38 None 6.79 3.35 None 7.93 4.12 None 7.06 6.35 None 4.59 4.96 None 6.70 7.87 N'one 6.53 6.60 None 6.82 8.14 None 6.71 10.90 None
553
are enclosed in a metal case which opens, as indicated, and which may be rotated by means of a n arm terminating in a micrometer screw, M. The smallest division on the micrometer corresponds t o a difference in index of about o.oooo5. The face of each prism is divided into two parts, A and B, by means of a groove so t h a t a drop of the standard liquid may be placed on one face (either A or B ) and a drop of the liquid t o be tested on the other face. For example, since the temperature coefficient of most solutions is nearly t h a t of water, water may be used as a standard when measuring the index of solutions. To obtain a dividing line free from color it is necessary t o use a monochromatic source of light, such as a sodium flame, or some compensating device. The former is sometimes inconvenient and the latter would considerably increase the cost of the instrument. A monochromatic red glass, G, was used in connection with a n electric light, L, and i t was found t h a t the dividing line is nearly as sharp as t h a t which obtains when a sodium flame is used. The lamp used was a 7.5 watt, I I O volt, frosted globe tungsten and
\
LEVEL,M O N K E YBATTERY Carbon Dioxide Per cent 2.09 2.11 2.17 2.30 1.98 2.12 3.31 3.40 3.46 4.10 3.67 3.43 3.62 3.97 3.65 3.40 4.40 4.06 4.81 4.86 4.96 4.84
Carbon Monoxide Per cent 0.019 0.009 0.0044 0.029 0.016 0.01
0 10068 0.006 0.007 0,008 0.0017 None iVone None None None None None None None None Sone
Carbon Dioxidein Methane Black Damp' Per cent Per cent 5.97 7.13 3.35 5.29 6.22 5.52 4.73 8.14 5.15 6.73 5.62 4.40 6.20 7.77 5.63 7.39 4.76 7.80 6.34 8.35 5.25 8.72 5.76 7.32 4.96 8.85 6.13 7.82 3.81 7.63 6.44 7.36 7.02 7.52 6.87 7.21 6.36 9.03 10.05 6.47 11.88 6.81 10.17 6.29
and Haldane, " T h e Investigation of Mine Sir," p. 124
~
THE PHILADELPHIA & READINGCOAL A N D I R O N COMPANY POTTSVILLE, P E N N S Y L V A N I A
A DIFFERENTIAL REFRACTOMETER B y G . A. SHOOE Received February 16, 1918
This instrument is the result of a n attempt t o develop a simple but accurate refractometer for measuring the difference in refractive index between two liquids. It is of the Abbe type but so constructed t h a t two liquids may be examined simultaneously and, therefore, if the index of one is known and if both have the same temperature coefficient, the index of the liquid in question may be accurately determined without knowing its temperature. The instrument as constructed by the writer is shown diagrammatically in Fig. I, and the optical system in Fig. 11. The refracting prisms P, P
FIG. I
FIG. I1
it was made a part of the instrument so t h a t no adjusting was necessary when once in place. I t is more convenient than daylight and it also produces a more uniform field. The refractometer was originally designed to measure the difference in index between hemolyzed and unhemolyzed blood, as it was discovered by Dr. F. H. Howard and the writer, some time ago, t h a t the amount of hemoglobin present in a given sample of blood causes its index t o vary markedly and, furthermore, t h a t the d i j e r e n c e i n iizdex ( h e m o l y z e d ami u n h e m o l y z e d blood) d e p e n d s o n l y u p o n the amoun't of h e m o g l o b i n p r e s e n t . Since the absorption bands of blood are in the green and blue parts of the spectrum a red glass is well adapted to this sort of measurement. After passing through the refracting prisms the light enters a telescope, T, provided with cross-wires as shown. Between the telescope objective, 0, and the prisms is a diaphram, D, provided with a shutter, S, and by adjusting this shutter the light from either A or B may be cut out. For instance, when the light from B is intercepted, the dividing line A', due t o the light from A, is seen; and when S intercepts the light from A, then B' is in the field. The distance
5 54
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
between these lines is measured by means of the micrometer M. When red light is used a difference in index can be measured with a n accuracy of about one in t h e fourth decimal place (i. e . , * O . O O O I ) , but with sodium light the accuracy is about *0.00005; t h a t is, if one measures the difference between the two lines by means of the micrometer, cleans the prisms, and makes a second measurement, the two values of the index difference calculated therefrom will agree within 0.0001 for red light and within o.oo005 for sodium light. The relation between the micrometer reading and the difference in index is very nearly linear, so t h a t by means of two solutions of known index and a comparison solution, the instrument can be easily calibrated. WILLIAMSCOLLEGS MASS. WILLIAMSTOWN.
Vol.
IO,
No. 7
chanical loss. This adjustable zero device consists of a small threaded metal sleeve fastened on the glass tube and fitted with a nut. Resting on the nut is a loose-fitting glass sleeve having a fine graduation. By turning the nut the graduation on the glass sleeve may be raised or lowered as desired. All metal surfaces t o which the mercury would have access are treated with bakelite, and the entire apparatus is securely mounted on a large wooden tray. The bulb and burette are also properly supported. The operation of the apparatus is conducted as follows: With the top removed and the stopcocks open, completely fill the tank with mercury, being careful not t o form any air traps in the Y-tube. Then draw the mercury well up into the bulb and burette, and after closing the stopcocks add sufficient mercury t o fill t h a t part of the chamber in the top of the tank. Place the top in the tank and fasten i t securely by the four bolts, D. By opening the stopcocks let the mer-
A VOLUMENOMETER By J. S. ROGERSA N D R. W. FREY Received February 19, 1918
Although there are numerous types of mercury displacement apparatus for measuring volume none has been found satisfactory for comparatively large pieces of leather. The apparatus described here, while based on the well-known displacement principle, possesses, it is believed, some new features. It is not only satisfactory for large pieces, but also permits of a decided economy in mercury since the chamber for immersion is in the shape of a rectangular parallelopiped instead of a cylinder or sphere. The apparatus was designed primarily for measuring test pieces of a maximum size 7 l / 4 X 3 in. in connection with the development of methods of determining loss from a mechanical wearing test of leather. It has also been found t o be very useful in determining the apparent density of leather. A description of the volumenometer and photographs (Figs. I and 11) follow: The immersion vessel consists essentially of the tank A and top B, both of cast iron and having accurately ground surfaces, C, so t h a t the top, when clamped on by means of the bolts, D , make a mercury-tight joint. The tank A has a chamber, E, 1 ~ / 8 in. wide, 8 in. long, and 3l/2 in. deep, cury down from the bulb and burette until it stands and the walls of this chamber are continued in the a t the same level in all parts of the apparatus. Set top B in such a manner that they converge t o the the two adjustable zeros, N and 0, so t h a t the graduasmall opening F in which is sealed, with shellac, the tions on the glass sleeves coincide with the-menisci short thistle tube G. The top has two posts, H,fto of the mercury, and take the zero reading on the burette. which the pieces t o be measured are fastened. Now draw the mercury again well up into the bulb I n the metal tube I , which passes through the wall and burette, close the stopcocks and remove the top. of the tank from the bottom of the chamber E, is Fasten the piece t o be measured onto the posts H sealed a heavy capillary glass Y-tube, J , fitted with the (Fig. I), replace and secure the top. Open the stopmercury-sealed stopcocks K. One arm of the Y-tube cock communicating with the bulb L and let the meris connected with the bulb L, and the other arm with cury run down slowly t o the zero mark a t N on the the burette M. Both the bulb and the burette are stem of the bulb and close the stopcock. Then open connected with the vacuum system. the stopcock connecting the burette and allow the By means of N and 0 the zero points on the two glass mercury t o gradually lower until it fills the tank and tubes may be easily adjusted t o coincide with the rises t o the zero mark a t 0 on the tube G, close t h e level of the mercury, which may change slightly from stopcock and read the burette (Fig. 11). The differtime t o time, due t o temperature variations and me- ence in readings will give the volume of the piece.
