Comprising File 1: Trek over the Donkya La Pass in North Sikkim, Oct 1932 File 2: Trek to Thangu Rest House, Sikkim, May-Jun 1935 File 3: Trek to Dzongri and the Guichi La, Sikkim, Sep-Oct 1935 File 4: Trek over Boriim La and Seba La, May-Jun 1936 File 5: Trek to Lhonak and Zemu valleys, Sikkim, autumn 1936