Apr., I935.] CURRENT TOPICS. 52I

the wind and hence greatly increase their resistance to a breeze. This new type boat is surprisingly fast and has easily beaten larger boats against which it has sailed. It will come up quicker and sail nearer the wind than the usual type boat.

C.

A More Powerful Gasoline.--( Science Service.) By using a gasoline with ideal Ioo octane antiknock rating, the Army has found a way to increase the power output of airplane engines by nearly a sixth to a third without increasing the weight of gasoline used. This new experimental aviation gasoline was composed half of iso-octane and half of good quality ordinary aviation gas- oline with ethyl addition.

These superior gasolines will cost more per gallon than present aviation fuels but since they will contain more power per pound, they promise to be actually more economical.

C.

Looking Into a Diesel's Interior.--( Science Service.) Using special glass windows resisting temperatures up to 3,500 degrees Fahrenheit, aviation research scientists have just discovered how fuel oil burns in a Diesel engine. By photographing on a motion picture film at the rate of 2,500 frames per second, A. M. Rothrock of the National Advisory Committee for Aeronautics Laboratories was able to demonstrate beyond question just how the fuel burned in the cylinder of a Diesel engine.

Previously it had been supposed that the oil began to burn as soon as it came in from the fuel jets. However, Mr. Rothrock's film proves that combustion occurs only after the fuel fills the firing space. Now that it is possible to see or photograph what is going on inside the cylinder this new technique should speed research in the Diesel engine field. For example, heretofore the character of various types of fuel jets could be determined only roughly. Now with the new windows and high-speed photography rapid checks on performance can be obtained.

C.

Japan's Metal Industries Exhibition.--Word comes from Japan that a metal industries exhibition will take place in the Commercial Museum at Osaka. It will be of three weeks duration, opening on the tenth and closing on the thirty-first of May, 1935. All nations are invited.

An excellent idea of what Japanese workers are accomplishing in the field of metallographic research may be had from the series