The Boy Allies with the Cossacks; Or, a Wild Dash Over the Carpathians is a historical adventure novel by Clair W. Hayes, first published in 1915. The story follows American boys Hal Paine and Chester Crawford as they participate in World War I, navigating dangerous situations to deliver an important message to the Grand Duke Nicholas of Russia. Their thrilling escapades include aerial combat and encounters with Russian Cossacks, reflecting the adventurous spirit of the era's juvenile fiction.
