These consolidated proceedings were brought to review the denial by the Assessors of Taxes of the Town of Lansing, Tompkins County, of exemption from realty taxes for the years 1954, 1955 and 1956 of relator's 800-acre farm in the township. Relator claims the exemption under subdivision 6 of section 4 of the Tax Law (now Real Property Tax Law, 420), the pertinent part of which makes exempt