Making of the Atomic Bomb

by Richard Rhodes

  “When our difficulties were solved through Dr. Weizmann’s genius,” continues Lloyd George, “I said to him: ‘You have rendered great service to the State, and I should like to ask the Prime Minister to recommend you to His Majesty for some honour.’ He said, ‘There is nothing I want for myself.’ ‘But is there nothing we can do as a recognition of your valuable assistance to the country?’ I asked. He replied: ‘Yes, I would like you to do something for my people.’ . . . That was the fount and origin of the famous declaration about the National Home for Jews in Palestine.”332

  The “famous declaration” came to be called the Balfour Declaration, a commitment by the British government in the form of a letter from Arthur Balfour to Baron Edmond de Rothschild to “view with favour the establishment in Palestine of a national home for the Jewish people” and to “use their best endeavours to facilitate the achievement of this object.”333 That document originated far more complexly than in simple payment for Weizmann’s biochemical services. Other spokesmen and statesmen were at work as well and Weizmann’s two thousand interviews need to be counted in. Smuts identified the relationship long after the war when he said that Weizmann’s “outstanding war work as a scientist had made him known and famous in high Allied circles, and his voice carried so much the greater weight in pleading for the Jewish National Home.”334

  But despite these necessary qualifications, Lloyd George’s version of the story deserves better than the condescension historians usually accord it. A letter of one hundred eighteen words signed by the Foreign Secretary committing His Majesty’s government to a Jewish homeland in Palestine at some indefinite future time, “it being clearly understood that nothing shall be done which may prejudice the civil and religious rights of existing non-Jewish communities in Palestine.”335 can hardly be counted an unseemly reward for saving the guns of the British Army and Navy from premature senility. Chaim Weizmann’s experience was an early and instructive example of the power of science in time of war. Government took note. So did science.

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  A heavy German artillery bombardment preceded the second battle of Ypres that began on April 22, 1915. Ypres was (or had been: it hardly existed anymore) a modest market town in southeastern Belgium about eight miles north of the French border and less than thirty miles inland from the French port of Dunkirk. Around Ypres spread shell-cratered, soggy downland dominated by unpromising low hills—the highest of them, Hill 60 on the military maps, volcanically contested, only 180 feet elevation. A line of Allied and, parallel northeastward, of German trenches curved through the area, emplaced since the previous November.

  Before then, the German attacking and the British defending, the two armies had run a race to the sea. The Germans had hoped to win the race to turn the flank of the Allies. Not yet fully mobilized for war, they even threw in Ersatz Corps of ill-trained high school and university students to bolster their numbers and took 135,000 casualties in what the German people came to call the Kindermord, the murder of the children. But at the price of 50,000 lives the British held the narrow flank. The war that was supposed to be surgically brief—a quick march through Belgium, France’s capitulation, home by Christmas—turned to a stagnant war of opposing trenches, in the Ypres salient as everywhere along the battle line from the Channel to the Alps.

  The April 22 bombardment, the beginning of a concerted German attempt at breakthrough, had driven the Canadians and French Africans holding the line at Ypres deep into their trenches. At sunset it lifted. German troops moved back from the front line along perpendicular communication trenches, leaving behind only newly trained Pioniere—combat engineers. A German rocket signal went up.336 The Pioniere set to work opening valves. A greenish-yellow cloud hissed from nozzles and drifted on the wind across no-man’s-land. It blanketed the ground, flowed into craters, over the rotting bodies of the dead, through wide brambles of barbed wire, drifted then across the sandbagged Allied parapets and down the trench walls past the firesteps, filled the trenches, found dugouts and deep shelters: and men who breathed it screamed in pain and choked. It was chlorine gas, caustic and asphyxiating. It smelled as chlorine smells and burned as chlorine burns.

  Masses of Africans and Canadians stumbled back in retreat. Other masses, surprised and utterly uncomprehending, staggered out of their trenches into no-man’s-land. Men clawed at their throats, stuffed their mouths with shirttails or scarves, tore the dirt with their bare hands and buried their faces in the earth. They writhed in agony, ten thousand of them, serious casualties; and five thousand others died. Entire divisions abandoned the line.

  Germany achieved perfect surprise. All the belligerents had agreed under the Hague Declaration of 1899 Concerning Asphyxiating Gases “to abstain from the use of projectiles the sole object of which is the diffusion of asphyxiating or deleterious gases.”337 None seemed to think tear gas covered by this declaration, though tear gases are more toxic than chlorine in sufficient concentration. The French used tear gas in the form of rifle grenades as early as August 1914; the Germans used it in artillery shells fired against the Russians at Bolimow at the end of January 1915 and on the Western Front first against the British at Nieuport in March. But the chlorine attack at Ypres was the first major and deliberate poison-gas attack of the war.

  As later with other weapons of unfamiliar effect, the chlorine terrorized and bewildered. Men threw down their rifles and decamped. Medical officers at aid stations were suddenly overwhelmed with casualties the cause of whose injuries was unknown. Chemists among the men who survived the attack recognized chlorine quickly enough, however, and knew how easy it was to neutralize; within a week the women of London had sewn 300,000 pads of muslin-wrapped cotton for soaking in hyposulfite—the first crude gas masks.338

  Even though the German High Command allowed the use of gas at Ypres, it apparently doubted its tactical value. It had massed no reserve troops behind the lines to follow up. Allied divisions quickly closed the gap. Nothing came of the attack except agony.

  Otto Hahn, a lieutenant in the infantry reserve, helped install the gas cylinders, 5,730 of them containing 168 tons of chlorine, originally at a different place in the line.339, 340 Shovel crews dug them into the forward walls of the trenches at firestep level and sandbagged them thickly to protect them from shellfire. To work them you connected lead pipe to their valves, ran the pipe over the parapet into no-man’s-land, waited for a rocket to signal a start and opened the valves for a predetermined time. Chlorine boils at—28.5° F unpressurized; it boiled out eagerly when released. But the prevailing winds had been wrong where Hahn’s team of Pioniere first installed the chlorine cylinders. By the time the High Command decided to remove them to Ypres along a four-mile front where the wind blew more favorably, Hahn had been sent off to investigate gas-attack conditions in the Champagne.

  In January he was ordered to German-occupied Brussels to see Fritz Haber. Haber had just been promoted from reserve sergeant major to captain, an unprecedented leap in rank in the aristocratic Germany Army. He needed the rank, he told Hahn, to accomplish his new work. “Haber informed me that his job was to set up a special unit for gas-warfare.”341 It seems that Hahn was shocked. Haber offered reasons. They were reasons that would be heard again in time of war:

  He explained to me that the Western fronts, which were all bogged down, could be got moving again only by means of new weapons. One of the weapons contemplated was poison gas. . . . When I objected that this was a mode of warfare violating the Hague Convention he said that the French had already started it—though not to much effect—by using rifle-ammunition filled with gas. Besides, it was a way of saving countless lives, if it meant that the war could be brought to an end sooner.

  Hahn followed Haber to work on gas warfare. So did the physicist James Franck, head of the physics department at Haber’s institute, who, like Haber and Hahn, would later win the Nobel Prize.342 So did a crowd of industrial chemists employed by I.G. Farben, a cartel of eight chemical companies assembled
in wartime by the energetic Carl Duisberg of Bayer.343 The plant at Leverkusen with the new lecture hall turned up hundreds of known toxic substances, many of them dye precursors and intermediates, and sent them off to the Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry for study. Berlin acquired depots for gas storage and a school where Hahn instructed in gas defense.

  He also directed gas attacks. In Galicia on the Eastern Front in mid-June 1915, “the wind was favourable and we discharged a very poisonous gas, a mixture of chlorine and phosgene, against the [Russian] enemy lines. . . .344 Not a single shot was fired. . . . The attack was a complete success.”345

  Because of its massive chemical industry, which supplied the world before the war, Germany was far ahead of the Allies in the production of chemicals for gas warfare. Early in the war the British had even been reduced to buying German dyestuffs (not for gas, for dyeing) through neutral countries; when the Germans discovered the subterfuge they proposed, with what compounding of cynicism and labored Teutonic humor the record does not reveal, to trade dyestuffs for scarce rubber and cotton.346 But France and Britain went immediately to work. By the end of the war at least 200,000 tons of chemical warfare agents had been manufactured and used, half by Germany, half by the several Allies together.

  Abrogating the Hague Convention opened an array of new ecological niches, so to speak, in weaponry. Types of gas and means of delivery then proceeded to diversify like Darwin’s finches. Germany introduced phosgene next after chlorine, mixing it with chlorine for cloud-gas attacks like Hahn’s because of its slow rate of evaporation.347 The French retaliated in early 1916 with phosgene artillery shells. Phosgene then became a staple of the war, dispensed from cylinders, artillery shells, trench mortars, canisters fired from mortarlike “projectors” and bombs. It smelled like new-mown hay but it was by far the most toxic gas used, ten times as toxic as chlorine, fatal in ten minutes at a concentration of half a milligram per liter of air. At higher concentrations one or two breaths killed in a matter of hours. Phosgene—carbonyl chloride—hydrolyzed to hydrochloric acid in contact with water; that was its action in the water-saturated air deep in the delicate bubbled tissue of the human lung. It caused more than 80 percent of the war’s gas fatalities.

  Chlorpicrin—the British called it vomiting gas, the Germans called it Klop—a vicious compound of picric acid and bleaching powder, came along next.348 German engineers used it against Russian soldiers in August 1916. Its special virtue was its chemical inertness. It did not react with the several neutralizing chemicals packed in gas-mask canisters; only the modest layer of activated charcoal in the canisters removed it from the air by adsorption. So a high concentration could saturate the charcoal and get through. It worked like tear gas but induced nausea, vomiting and diarrhea as well. Men raised their masks to vomit; if the Klop had been mixed with phosgene, as it frequently was, they might then be lethally exposed. Chlorpicrin’s other advantage was that it was simple and cheap to make.

  The most horrible gas of the war, the gas that started a previously complacent United States developing a chemical-warfare capacity of its own, was dichlorethyl sulfide, known for its horseradish- or mustard-like smell as mustard gas.349 The Germans first used it on the night of July 17, 1917, in an artillery bombardment against the British at Ypres. The attack came as a complete surprise and caused thousands of casualties. Defense in the form of effective masks and efficient gas discipline had caught up with offense by the summer of 1917; Germany introduced mustard gas to break the deadlock, just as it had introduced chlorine before. Shells marked with yellow crosses rained down on the men at Ypres. At first they experienced not much more than sneezing and many put away their masks. Then they began vomiting. Their skin reddened and began to blister. Their eyelids inflamed and swelled shut. They had to be led away blinded to aid stations, more than fourteen thousand of them over the next three weeks.

  Though the gas smelled like mustard in dense concentrations, in low concentrations, still extremely toxic, it was hardly noticeable. It persisted for days and even weeks in the field. A gas mask alone was no longer sufficient protection. Mustard dissolved rubber and leather; it soaked through multiple layers of cloth. One man might bring enough back to a dugout on the sole of his boot to blind temporarily an entire nest of his mates. Its odor could also be disguised with other gases. The Germans sometimes chose to disguise mustard with xylyl bromide, a tear gas that smells like lilac, and so it came to pass in the wartime spring that men ran in terror from a breeze scented with blossoming lilac shrubs.

  These are not nearly all the gases and poisons developed in the boisterous, vicious laboratory of the Great War. There were sneezing gases and arsenic powders and a dozen tear gases and every combination. The French loaded artillery shells with cyanide—to no point except hatred, as it turned out, because the resulting vapors were lighter than air and immediately lofted away. By 1918 a typical artillery barrage locomoting east or west over the front lines counted nearly as many gas shells as high-explosive.350 Germany, always logical at war to the point of inhumanity, blamed the French and courted a succession of increasingly desperate breakthroughs. The chemists, like bargain hunters, imagined they were spending a pittance of tens of thousands of lives to save a purseful more. Britain reacted with moral outrage but capitulated in the name of parity.

  It was more than Fritz Haber’s wife could bear. Clara Immerwahr had been Haber’s childhood sweetheart. She was the first woman to win a doctorate in chemistry from the University of Breslau. After she married Haber and bore him a son, a neglected housewife with a child to raise, she withdrew progressively from science and into depression. Her husband’s work with poison gas triggered even more desperate melancholy. “She began to regard poison gas not only as a perversion of science but also as a sign of barbarism,” a Haber biographer explains. “It brought back the tortures men said they had forgotten long ago. It degraded and corrupted the discipline [i.e., chemistry] which had opened new vistas of life.”351 She asked, argued, finally adamantly demanded that her husband abandon gas work. Haber told her what he had told Hahn, adding for good measure, patriot that he was, that a scientist belongs to the world in times of peace but to his country in times of war.352 Then he stormed out to supervise a gas attack on the Eastern Front. Dr. Clara Immerwahr Haber committed suicide the same night.

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  The Allied campaign at Gallipoli began on April 25, 1915. The rough, southward-descending Gallipoli Peninsula looked westward toward the Aegean; eastward, across the narrow strait known as the Dardanelles—to the ancients and to Lord Byron, the Hellespont—it faced Turkish Asia. Capture the peninsula; control the Dardanelles, then the Sea of Marmara above, then the narrow Bosporus Strait that divides Europe from Asia, then Constantinople, and you might control the Black Sea, into which the Danube drains—a vast flanking movement against the Central Powers. Such were the ambitions of the War Cabinet, chivvied by Winston Churchill, for the Dardanelles campaign. The Turks, whose land it was, backed by the Germans, opposed the operation with machine guns and howitzers.

  One Australian, one New Zealand, one French colonial and two British divisions landed at Gallipoli to establish narrow beachheads. The water of one beachhead bay churned as white at first as a rapid, the Turks pouring down ten thousand rounds a minute from the steep cliffs above; then it bloomed thick and red with blood. Geography, error and six Turkish divisions under a skillful German commander forestalled any effective advance. By early May, when a British Gurkha and a French division arrived to replace the Allied depletions, both sides had chiseled trenches in the stony ground.

  The standoff persisted into summer. Sir Ian Hamilton, the Allied commander, Corfu-born, literary, with a Boer-stiffened right arm and the best of intentions, appealed for reinforcements. The War Cabinet had reorganized itself and expelled Churchill; it assented with reluctance to Hamilton’s appeal and shipped out five divisions more.

  Harry Moseley shipped out among them. He was a
signaling officer now, 38th Brigade, 13th Infantry Division, one of Lord Kitchener’s New Army batches made up of dedicated but inexperienced civilian volunteers. At Gibraltar on June 20 he signaled his mother “Our destination no longer in doubt.”353 At Alexandria on June 27 he made his will, leaving everything, which was £2,200, to the Royal Society strictly “to be applied to the furtherance of experimental research in Pathology Physics Physiology Chemistry or other branches of science but not in pure mathematics astronomy or any branch of science which aims merely at describing cataloguing or systematizing.”354

  Alexandria was “full of heat flies native troops and Australians” and after a week they sailed on to Cape Helles on the southern extremity of the Gallipoli Peninsula, a relatively secure bay behind the trench lines.355 There they could ease into combat in the form of artillery shells lobbed over the Dardanelles to Europe, as it were, from Turkish batteries in Asia. If men were bathing in the bay a lookout on the heights blew a trumpet blast to announce a round coming in. Centipedes and sand, Harry dispensing chlorodyne to his men to cure them of the grim amebic dysentery everyone caught from the beaches, Harry in silk pajamas sharing out the glorious Tiptree blackberry jam his mother sent. “The one real interest in life is the flies,” he wrote her. “No mosquitoes, but flies by day and flies by night, flies in the water, flies in the food.”356