Probably the strangest device of all that Lieut. Doolittle has been called upon to test in Mr. Guggenheim's war against fog is a sort of heat cannon that goes forth to combat like a fire-breathing dragon of old. Like the enemies of the dragon, the fog is supposed to curl up and die before the scorching breath of the "hot air artillery" although the fundamental principle behind the device is a great deal more scientific than such an explanation sounds. It is, in brief, based on the known fact that fog forms only in a very narrow temperature zone which lies between the saturation and precipitation points of the atmosphere. If the air grows a little colder the fog turns into rain and falls; if it is warmed very slightly the mist disappears and the air is once more normally clear, although its humidity is very close to the maximum. Brigands of the Moon (The Book of Gregg Haljan) PART TWO OF A FOUR-PART NOVEL _By Ray Cummings_ [Illustration: _I turned back to look at the Planetara._] Out of awful space tumbled the Space-ship _Planetara_ towards the Moon, her officers _dead_, with bandits at her helm--and the controls out of order! My name, Gregg Haljan. My age, twenty-five years. My occupation, at the time my narrative begins, in 2075, was third officer of the Interplanetary Space-ship _Planetara_. Thus I introduce myself to you. For this is a continuation of the book of Gregg Haljan, and of necessity I am the chief actor therein. I shall recapitulate very briefly what has happened so far: Unscrupulous Martian brigands were scheming for Johnny Grantline's secret radium-ore treasure, dug out of the Moon and waiting there to be picked up by the _Planetara_ on her return trip from Mars. The _Planetara_ left, bound for Mars, some ten days away. Suspicious interplanetary passengers were aboard: Miko and Moa, a brother and a sister of Mars; Sir Arthur Coniston, a mysterious Englishman; Ob Hahn, a Venus mystic. And small, effeminate George Prince and his sister, Anita. Love, I think, was born instantly between Anita and me. I found all too soon that Miko, the sinister giant from Mars, also desired her. [Illustration] As we neared the Moon we received Grantline's secret message: "Stop for ore on your return voyage. Success beyond wildest hopes!" But I soon discovered that an eavesdropper in an invisible cloak had overheard it! Soon afterwards Miko accidentally murdered a person identified as Anita Prince. Then, in the confusion that resulted, Miko struck his great blow. The crew of the _Planetara_, secretly in his pay, rose up and killed the captain and all the officers but Snap Dean, the radio-helio operator, and myself. I was besieged in the chart-room. George Prince leaped in upon me--and put his arms around me. I looked at him closer--only to discover it was Anita, disguised as her brother! It was her brother, George, who had been killed! George had been in the brigands' confidence--thus Anita was able to spy for us.