21. IOR/V/27/420/89 Reference (shelfmark): IOR/V/27/420/89 Title: India. Survey of India, Trigonometrical Branch Spirit-Levelled heights: No 1: Assam 1901-02. Dehra Dun, 1863-1903 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1863-1903 Extent: 1 volume
22. IOR/V/27/420/104 Reference (shelfmark): IOR/V/27/420/104 Title: Pogson, Norman R., Telegraphic determinations of the difference of longitude between Karachi, Avanashi, Roorkee, Pondicherry, Colombo, Jaffna, Muddapur and Singapore, and the Government Observatory, Madras. Madras: Lawrence Asylum Press, 1884 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1884 Extent: 1 volume
23. IOR/V/27/420/127 Reference (shelfmark): IOR/V/27/420/127 Title: Great Britain. Colonial Office, Empire Conference of Survey Officers, 1928. Report of proceedings. London, 1929 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1929 Extent: 1 volume
24. IOR/V/27/420/27 Reference (shelfmark): IOR/V/27/420/27 Title: Waugh, Sir A Scott, Instructions for topographical surveying. Roorkee: Civil Engineering College Press, 1853 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1853 Extent: 1 volume
25. IOR/V/27/420/55 Reference (shelfmark): IOR/V/27/420/55 Title: Clancey, J C, Calculating tables in English... Part 1. Authorised edition (4th). Rangoon, 1902 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1902 Extent: 1 volume
26. IOR/V/27/420/106 Reference (shelfmark): IOR/V/27/420/106 Title: Burrard, S G, Report on the trigonometrical results of the earthquake in Assam. 1898 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1898 Extent: 1 volume
27. IOR/V/27/420/52 Reference (shelfmark): IOR/V/27/420/52 Title: Eccles, J, Instructions for taking magnetic observations for the Survey of India Department. Dehra Dun, 1896 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1896 Extent: 1 volume
28. IOR/V/27/420/72 Reference (shelfmark): IOR/V/27/420/72 Title: India. Survey of India, Trigonometrical Branch Spirit-Levelled heights: Nos 2-3: Southern India 1869-75. Dehra Dun, 1863-1903 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1863-1903 Extent: 1 volume
29. IOR/V/27/420/73 Reference (shelfmark): IOR/V/27/420/73 Title: India. Survey of India, Trigonometrical Branch Spirit-Levelled heights: Nos 1-6: Madras Presidency 1869-90. Dehra Dun, 1863-1903 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1863-1903 Extent: 1 volume
30. IOR/V/27/420/74 Reference (shelfmark): IOR/V/27/420/74 Title: India. Survey of India, Trigonometrical Branch Spirit-Levelled heights: Nos 1-3: Bombay Presidency 1874-80. Dehra Dun, 1863-1903 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1863-1903 Extent: 1 volume