Reported in Scientific American, this Week in World War I: November 20, 1915
Italy declared war on Austria-Hungary on May 23, 1915. It did not go well. Although the Italians were numerically superior, the troops of the Austria-Hungary empire held the high ground: in some cases, the exceptionally high ground of the eastern Alps at elevations of 10,000 feet. Italian troops were tasked with attacking up steep mountainsides. In some documented cases, such as during one of the many battles of Mount Mrzli Vrh (now in Slovenia, then part of the Austria-Hungary Empire), the defending Austrians simply hurled large boulders at the Italians struggling up the steep slopes.
The cover of the November 20, 1915, issue of Scientific American illustrates such an event, although there is no information inside the issue about where or when this incident occurred. The only information about the image is this: “Return to primitive warfare in the Alps—Austrians hurling down rocks to stop an Italian charge.”
The casualties on the Italian front were horrendous: from repeated, mass, futile attacks, and from cold, the altitude, avalanches and starvation.
An excellent description of the military, political and cultural aspects of the First World War from the Italian perspective: “The White War: Life and Death on the Italian Front 1915-1919,” by Mark Thompson, Basic Books, 2009.
A photograph of Austrian troops setting up piles of boulders:
Our full archive of the war, called Scientific American Chronicles: World War I, has many articles from 1914–1918 on various battlefields of the First World War. It is available for purchase at www.scientificamerican.com/products/world-war-i/