1875 3 March. Ohinemuri Goldfield was opened
1876 August 3. Karangahake Gold Mining Company's battery with 12 head of stampers started
  August 16. Wick’s battery of nine stamps on Mangakara Creek started
  August 30. Waitekauri Battery started
1877 January 9. Perry’s battery of 20 stamps at Owharoa started
1878 Late 1878 saw McCombie and Lee testing a large reef on Pukewhau spur.
1880 Nicholl and Majurey leave the Te Aroha goldfield late 1880, and venture to the Waihi Plains.
1881 17 January, Nicholl made the first public announcement of his find
  End January. Nicholl had trial parcel crushed at the Smile of Fortune Battery Owharoa.
  16 February, he applied for three acres, one rood, and 26 perches as his Martha claim. Granted 24 March.
  Late June FA White set up Martha Gold Mining and Quartz Crushing Company
1882 24 May. Martha Battery completed, officially opened with a gala event.
  23 June. Waihi Company Battery completed (with Cabbage Tree Creek (Waimata Stream) water race)
1883 31 March. Martha Extended Company was launched, Mr J. H. Moore manager (amalgamation of Martha, Waihi and Young Colonial). Not Dulcibel
  April. Firth and Clark Battery at Waiorongomai opened
  October-November, Martha Extended Company add 10 stamps to its battery, making 30
1885 Rosemont, Union and Silverton mines taken up
  12 August. John McCombie marked out Silverton claim
1886 Silverton Company using 10 stamps at Martha Battery, and saving tailings
1887 15 October, Martha and Silverton manager John H. Moore left for Maratoto. Tributers took over (includes Hollis)
  December. Waihi Gold Mining Company Limited floated in London
1888 Construction of Waihi Battery on Union Hill commenced
  February. Martha Extended Company mine and battery for sale
1890 23 April. Battery sold to Thomas Henry Russell for £3000. Offered to the Waihi Company on 7 July
1891 June. Silverton Company purchased Martha Battery; became Silverton Battery
  December. Mangatoetoe Stream water race constructed, followed shortly by Mangakiri Stream water race
1893 April. Silverton Company fully adopted Cassel process (cyanide); the first in Waihi
1894 May. Cyanide plant at the Waihi Battery complete
1895 Silverton mine sold. Became Waihi-Silverton Gold-mining Company (Limited), Glasgow
  Silverton Tramway constructed, dam on Ohinemuri River
  Three in-ground kilns constructed at mine, dry crushing at battery
  June. Union-Waihi Gold-mining Company Limited split off from Waihi Gold Mining Co., combining the Amaranth, Rosemont, Golden Run, and Union Special Claims
1896 4 April. Upgraded Silverton Battery officially opened. Dry crushing. H.H. Adams the manager
1898 Victoria Battery starts on first 100 stamps
1899 Union-Waihi Company purchased Silverton Company and battery, which became the Union Battery. Converted to wet crushing
1901 November. Waihi Gold Mining Company took over the Waihi-Union Company, and the Union Battery of 40 stamps
1902 Auxiliary power in form of steam engine and boiler installed at Union Battery. Tramway connection to Martha mine made
  16 September. Commenced crushing
1903 A new dam and penstock completed, with Leffel wheel
1909 August. One tube mill added to the plant
1911 18 January. Superintendent Barry denies rumour of intention to close the Union mill
  February. The Waihi Gold Mining Company shut down Union Mill
  H.H. Adams purchases the Union Mill, and Waihi Gladstone mine
1912-13 Waihi Battery on Union Hill closed
1913-15+ It seems likely that the Union Battery was "cleaned up" and removed by H.H. Adams