Star of David, PH, Leeds Phosphate Works, Image by StuE, Found by Garry J.
LEEDS / PHOSPHATE / WORKS // HP ligate at centre of Star of David
Leeds Phosphate company seal:-
Company No: 40783; Leeds Phosphate Works Ltd. Incorporated on 12/2/1894 β βTo carry on the business of Agricultural Chemists and Artificial Manure Manufacturers and Dealers in Artificial manures of all kinds.β Dissolved at Extra Ordinary General Meeting at Newcastle-upon-Tyne 30/9/1921. From National Archives, Kew.
See also Hoyermann Phosphate Factory, Hannover, seals from Germany where Gerhard Hoyermann developed the process of producing plant fertiliser from the phosphorus slag of blast furnaces. The PH / HP may actually stand for Hoyermann's Phosphate.