684 Biographical Memoirs The normal academic life so recently re-established was interrupted by the start of the first world war.The teaching routine was altered and many of the professors had their research efforts diverted to military aspects.Mobilization and the consequent increase in rail traffic had revealed inadequacies in the strength of much of the railroad tracks and Timoshenko was asked for advice on how to strengthen them.He simplified the problem to one of a beam on an elastic foundation and in this way was able to show immediately how the stresses depended on the dimensions of the rail and the rigidity of the track. The war with Germany also marked the beginning of a period of great social and political upheaval in Russia.The next few years were very trying for Timoshenko and his family,but it is characteristic of him that during this time he wrote and succeeded in getting published an elementary book on Strength of materials without calculus.Conditions worsened for him and his family after 1914 to the point where he decided to leave Russia.The Bolshevik grip on the country was tightening and it was felt that the professors should leave for Yugoslavia which had declared its willingness to accept Russian refugees. It was hoped that Poland would shortly enter an alliance with the Volunteer Army and drive the Bolsheviks from power,but events proved otherwise and there was to be no return to the homeland.The journey to Yugoslavia was not without incident.The train that took Timoshenko and his family from Kiev was the last that managed to leave,and they were able to board it only because the official in charge of the evacuation happened to have been one of his students Timoshenko had been offered the chair of strength of materials in Zagreb and, knowing the difficulties in obtaining accommodation there,had decided to find temporary rooms in a nearby village.In this he was greatly helped by an engineer who had studied one of Timoshenko's books while a prisoner of war;Timoshenko never dreamt that his book could have such practical value!When the academic year started it was necessary to find accommodation in Zagreb itself,but this proved almost impossible and Timoshenko and his family were obliged to move into the rooms intended as his future office and laboratory.It was fortunate that these rooms had electricity,gas and water,for they were to be his home for two years.While a bed was purchased for Timoshenko and Alexandra,the children slept on mattresses of hay-filled sacks on beds made from stools lashed together with rope.The children were taught Croatian at school while Timoshenko taught himself by reading the paper and from discussions with the Croatian professor of theoretical mechanics who also knew Russian.After his first year of teaching he spent part of the summer vacation touring Western European engineering laboratories.In London he found that,although he could read English without difficulty,he was not sufficiently accustomed to English pronunciation to understand the spoken language.It is typical of his untiring energy and broad interest that he should remedy this situation by attending a course on Egyptian culture at the British Museum. In Zagreb he also resumed his scientific work and published several papers in English with the help of R.V.Southwell and A.E.H.Love.One of these was a discussion of the corrections to the differential equation for transverse