In early 1914, Europe was in the midst of the largest war it had yet experienced. German physicist Albert Einstein had been waiting three years to verify his recent work on the effects of gravity on light. The only way he could prove (or indeed, disprove) his theory was by measuring how much (if at all) the path of light changed when near a large mass. With a total eclipse forecast for August of that year, it was a perfect opportunity to put his ideas to the test, after an unsuccessful attempt by astronomer Charles Dillon Perrine in 1912. 

He had previously enlisted help from his associate Erwin Findlay-Freundlich, an astronomer at the Berlin Observatory, who had analysed existing eclipse photographs to see if the effect could be observed. However, Freundlich was unable to source any suitable images – and so Einstein hoped that new photographs from the upcoming eclipse would be more helpful. 

Around the same time, a team at the Lick Observatory in California was planning an expedition to view the 1914 eclipse from the then Russian Empire. With members such as W. W. Campbell (the observatory’s director) and Herber D. Curtis (an established astronomer), the team was well prepared to perform the light-bending experiment alongside their previously planned agenda for the eclipse. 

The experiment was unsuccessful, with Campbell and Curtis writing that they “shared the ill fortune of several other large eclipse parties in Russia in its failure to secure any results, because of unfavourable weather conditions”. One such party was from the Argentine National Observatory, who in an expedition to Feodosia in Crimea, had also set out to perform the light bending experiment. Like the Lick team, they were greeted by clouds and were unable to capture any images of scientific interest. The Argentine party were meant to be joined by a party from the Berlin Observatory led by Freundlich. 

But for the observers scattered across the Russian Empire, the outbreak of the First World War not even a month prior to the eclipse resulted in their expedition equipment being stuck. Campbell had reached Kyiv on July 20, 1914, prior to the declaration of war on Serbia by Austria-Hungary. He had made extensive travel plans whilst on the expedition to allow his sons to visit key astronomical events and observatories in the Russian Empire, which eventually did not happen as international peace crumbled. In the week following their arrival, they were oblivious to the situation in Europe. It was not until July 30, 1914, on a visit to Kyiv, that the Lick party would discover that Europe was at war and that Russia had begun mobilising its troops. On August 2, 1914, Robert Filopowitch Foghel from the University of Kyiv alerted the party that Germany had declared war against Russia. Campbell wrote to the British Consul in Kyiv requesting that the eclipse site be staffed with two policemen to protect the expedition. The imperial government allowed the Lick and Argentine parties to observe the eclipse.

The Lick party would shortly after flee to London through the Baltics to avoid encountering the war fronts. Their equipment was later sent to the observatory in Odessa, part of the Russian Empire at the time (which is now modern-day Ukraine). Fruendlich’s German party however were all arrested. The older members were deported, and the younger members were held as prisoners of war to be used in a prisoner exchange with Germany. Following Germany’s occupation of Odessa, Freundlich (with the support of Einstein) attempted to convince the Ministry of Education to have soldiers retrieve their equipment. However, it wouldn’t arrive back in Germany until 1923, nearly a decade later. The Lick team was a bit more fortunate, on account of the United States remaining neutral in the war until the latter stages. They received their equipment back on August 15, 1917, after it being stored at the Russian National Observatory and kept in good condition. 

The British party to Sweden, on the other hand, under an expedition organised by the Joint Permanent Eclipse Committee (JPEC), had better fortunes – for both their scientific agenda and their own well-being! 

The expedition party, which included Jesuit astronomers Father Cortie and Father O’Conner, had initially planned to travel to Kyiv. However, the government of the Russian Empire initially refused the request, on account of their laws that categorically banned Jesuits from their country. As a result, the JPEC decided to divide the expedition and instead have Father Cortie lead an expedition to Härnösand, Sweden. Another expedition by the JPEC travelled to Minsk, now Belarus, but was greeted by clouds. Another British expedition from Cambridge travelled to Feodosia, now Crimea, and one from Kensington travelled to Kyiv, now Ukraine. It turned out that both Jesuit astronomers had later been granted permission to enter the empire, but by sheer luck, nobody had relayed the message to them! Otherwise, they likely would have found themselves imprisoned – much like Freundlich’s expedition party upon the mobilisation of the Russian Empire in the war. The British teams also had to leave their equipment in the Empire to be forwarded back to England after the war. 

Despite having made little arrangements for where to set up an observation site, the British team departed from Hull in England, on July 28, 1914, the day that Austria-Hungary declared war on Serbia. Thanks to the assistance and generosity of the Swedish eclipse committee and a Dutch expedition party from Valkenburg, the British joined the Valkenburg team at the Technical School in Härnösand and were granted permission to freely make use of the facilities. The British group arrived in Härnösand on August 3, 1914, and quickly set up their equipment on a field at the back of the school. 

Although Sweden maintained neutrality during the war, the country had still mobilised its armed forces. This meant that the expedition parties were required to present themselves to the authorities on each day of their stay in the town. Despite this, locals of the town and students at the school supported the observers generously – in the setup of the equipment, helping perform their morning drills, and on the day of the eclipse itself. Three students from the school produced a drawing of the corona. 

On the morning of the eclipse, a large group of spectators “dressed in their best clothes” congregated on the field with their dark glasses in hand. The weather conditions, unlike for the unfortunate observers in Russia, were perfect for observing the eclipse. The expedition party reported that the spectators remained extremely quiet, as though keen to avoid disrupting the group’s scientific observations. 

Just before totality, a nip of cold consumed the air. The corona was brilliantly brighter than usual, with both Mercury and Venus shining in the darkness of the sky. The British party were able to secure five detailed photographs of the corona, using a 20-inch coronagraph. These showed both solar prominences and coronal streamers. Another four photographs were captured with 30-inch Abney coronagraphs, showing the corona spanning as far out as two diameters of the Sun. A final, small-scale photograph was captured using a 12-inch coronagraph, which showed the extension of coronal streamers. Additional photos also were captured out of totality. 

Due to the developments in the war, the team was pressured to leave the country as soon as they could. Photographs were developed by August 22, 1914, and the team quickly dismounted all their instruments to board the first train for Stockholm. 

Incredibly, during their travels, the group had to be escorted by armed vessels through two minefields that the Swedish had set up. On their journey by boat back to the United Kingdom, they were intercepted by a British cruiser warning them that the German armed forces had set up floating mines directly in their path across the North Sea. As a result, the team had to prepare their lifeboats and divert their journey towards the north of Scotland. 

They were later intercepted once again to be warned of the dangers of the German’s floating mines. But they were able to travel closely along the coast of Scotland and northern England unharmed, arriving at the River Tyne in England under the escort of three torpedo boats on August 31, 1914.