
Sullivan heterodyne wavemeter model K5, No. 21 1922
1922
1922
1905-1920
1910
1908
1911
1924
1912
1912-1918
1917
1915
1914
1971-1900
1914-1918
1914-1918
1914-1918
1914-1918
1915-1825
1915-1917
17th July 1905
1907
1923
1922
circa 1913
1924
circa 1918
circa 1919
1917
1905
1910
1921
1909
1915-1920
1914-1917
1917-1920
1917-1919
1918-1920
1912
1904
1918
1920-1923
1916
1914-1918
1914-1918
1914
1914-1918
1918
17th July 1905
17th July 1905
1905-1907
1905