Incendiary Jelly

"Red fire clouds kept creeping high and the tower of the Parliament Building stuck out black against the background of the red sky. During the night we thought the whole of Tokyo had been reduced to ashes."

A Jap broadcaster thus described the havoc wrought by last fortnight's great B-29 fire raid on the Japanese capital. U.S. airmen gave much of the credit to a new type of incendiary bomb called the M-69.

The military use of fire, which goes back at least to Samson's day (he tied firebrands to the tails of 300 foxes and loosed them in the fields of the Philistines) has been developed in World War II to a fearsome degree. At the beginning of the war, both sides relied mainly on thermite and magnesium-filled bombs. Such bombs, as every air-raid warden knows, burn with terrible fury but are comparatively easy to put out if attacked in time.

The U.S. Army, casting about for a better and more easily produced bomb, found an answer in M-69, developed by the Standard Oil Development Co. (N.J.), an Esso research outfit.

The Esso incendiary is a 6 1/2 lb., 19 in. length of six-sided pipe filled with gasoline thickened to a sticky, raspberry-pink jelly by the addition of a still-secret powder. This oil-bomb produces almost twice as much heat in proportion to weight as magnesium and spreads destruction much faster.

Dropped in loose clusters of 14, or "amiable" clusters of 38, the finless oil-bombs are exploded by a time fuse four or five seconds after landing. Thereupon M-69s become miniature flamethrowers* that hurl cheesecloth socks full of furiously flaming goo for 100 yards. Anything these socks hit is enveloped by clinging, fiery pancakes, each spreading to more than a yard in diameter. Individually, these can be extinguished as easily as a magnesium bomb. But a single oil-bomb cluster produces so many fiery pancakes that the problem for fire fighters, like that of a mother whose child has got loose in the jam pot, is where to begin.

While Jap cities blazed, the R.A.F. was dropping on Germany the biggest explosive bomb of all. Called variously "volcano bomb," "townbuster" and "Ten-Ton Tess" (eleven tons, by U.S. measure), it carves an enormous crater (see cut), tossing up divots weighing five tons apiece.

* Esso's gasoline jelly is also used in the Army's flamethrower, affectionately called the "G.I. hot foot" (TIME, Jan. 31, 1944).

This file is automatically generated by a robot program, so reader's discretion is required.