216 



SCIENCE 



[Vol. liV, No. 1417 



bases. A discussion of plate surfaces tends to 

 show that correct design should be for long wear 

 of cloth and proper drainage. Also that the con- 

 tact area of the cloth does not reduce the net 

 filtering area as might be supposed. The filter 

 press comprises most filter area per unit of floor 

 space, can employ high pressures, has low repair 

 costs, produces the driest cake, is economical in 

 clothing, can be operated by cheap labor and is 

 the most universal and widely used filter appara- 

 tus to-day. Eleven plant installation views are 

 given. 



A symposium on the chemistry of gases and 

 fuel was also held with C. H. Stone chairman 

 and E. S. McBride secretary. The following four 

 major subjects were discussed: 



(a) Coke-oven problems, discussion to be 

 opened by W. H. Blauvelt, F. W. Spere and 

 others. 



(6) Low temperature carbonization of coal, 

 discussion to be opened by H. C. Poetee. 



(c) Gas works control, discussion to be opened 

 by E. C. Uhlig, J. R. Campbell and O. A. Moa- 



HOUS. 



(d) Gas analysis and its applications, discus- 

 sion to be opened by G. W. Jones, E. E. Weavee 

 and A. H. White. 



Two new methods for determining light oil in 

 coTce oven gas: Aethue L. Davis. The most 

 accurate and thoroughly reliable method that has 

 been developed to the present time utilizes acti- 

 vated carbon as the absorbing medium. Absorp- 

 tion of the light oil is rapid and the carbon is 

 very convenient to handle. The absorbed light 

 oil is removed by distillation of the enriched 

 carbon with cresol and the subsequent treatment 

 of the distillate with caustic. The true light oil 

 recovered, uncontaminated with wash oil, may be 

 examined and its quality determined. A very 

 satisfactory means of absorbing light oil is to 

 pass the gas through a plate and beU tower, lab- 

 oratory size, using cresol as the absorbing medi- 

 um. A tower of this type is imperative since 

 incomplete absorption will be obtained using 

 other than this general type of equipment when 

 any liquid absorbent is used. The cresol is 

 stripped of the light oil and the distillate agi- 

 tated with caustic. The light oil obtained is true 

 light oil with no high boiling ends due to the 

 lower boiling portions of wash oil being present. 



Standardising gas comiu-stion iy premixing 

 portions of air with gas: N. H. Gellee. 



A chemically controlled automobile: Geoeqe G. 

 Beown, Je. The average motor car wastes twice 



as much energy as is converteii into useful work. 

 The thermal efficiency averages not over 15 per 

 cent. This loss, entirely preventable, is a waste 

 of a valuable and limited natural resource, petro- 

 leum. In all industrial combustion problems 

 increased efficiency can be obtained by returning 

 as much heat as possible from the exhaust gases 

 to the combustion zone by preheating the air. 

 Another factor, known as turbulence, which 

 results from the velocity of the mixture entering 

 the cylinder, has an equally noticeable effect 

 upon the rate of combustion. Eepeated tests 

 have shown that 30, 35, 40 miles per gallon and 

 even more may be obtained driving at constant 

 speed along a level highway and burning a lean 

 hot mixture. It has been found that the two 

 variables, temperature of air and manifold suc- 

 tion, are sufficient in themselves to supply all the 

 automatic control desired. Working along these 

 lines a carbureter has been designed from a scien- 

 tific and mathematical standpoint that can be 

 made to deliver a mixture of any proportions 

 desired under any conditions. It has been found 

 possible to obtain 35 to 40 miles per gallon on a 

 standard Ford touring car with equally quick 

 acceleration and even more flexibility than could 

 be obtained vdth standard equipment giving 20 

 miles per gallon under the same conditions. 



Theoretical maximum temperature: George G. 

 Beown, Je. (1) A comparison of the values for 

 specific heats of the products of combustion as 

 obtained by the various investigators. (2) Cal- 

 culation of maximum temperatures using a table 

 of mean specific heats, or thermal capacities: a. 

 Estimating temperatures and solving by trial and 

 error; 6. The graphical method of Damour. 

 (3) Calculation of maximum temperature using 

 the equations for thermal capacities: a. Alge- 

 braic solution; 6. Slide rule solution; c. Graph- 

 ical solution. 



The formation of oxides of nitrogen in the 

 slow combustion and explosion methods in gas 

 analysis: G. W. Jones and W. L. Parker. Pro- 

 cedure and results of investigation are given 

 showing the amounts of oxides of nitrogen 

 formed when gases are analyzed by the slow 

 combustion and explosion method. The following 

 conclusions were obtained: The production of 

 oxides of nitrogen by the slow combustion method 

 when the time of burning is not more than three 

 minutes and the wire heated not greater than a 

 bright yellow is mthin the experimental error in 

 routine gas analysis. Under the above conditions 

 not more than .003 c.c. of oxides of nitrogen 



