Salinometer

...; transferred from the Ministerie van Marine (Department of the Navy), The Hague, to the museum, 1883

ObjectNumber: NG-MC-1060

Salinometer, incomplete. It consists of a copper container with two pipes at the bottom. One pipe has a cock and is the inlet, through which water from the boiler is admitted; it fills the container and is drained via the overflow, which is connected to the outlet pipe. This system made it possible to measure a constant flow of water, thus determining an average. When the inlet is shut off, the water remaining in the container can be drained by opening a second cock in the bottom of the container, which is connected to the outlet. Inside the container, a brass cylinder for the hydrometer (now missing) and a thermometer are fitted; both can be lifted out. On the outside a small lamp with a round reflecting mirror is fitted on an arm, for reading the salinometer in the dark hold of the ship. The whole can be fitted to a boiler casing with the plate fixed to its back. The inscription on the front carries the British coat of arms.

Salinometers were used to measure the proportion of salt in the boiler water in order to prevent the boilers salting up. If, through boiling, the proportion of salt in the brine exceeded 2/32, the brine was blown off and new seawater admitted into the boiler.

The Dutch Navy introduced salinometers for use on all its steam vessels in 1852.¹¹HNA 2.12.01 Min. Marine, inv. no. 3970.

H. Huijgens, ‘De scheepsstoomketels’, Verhandelingen en berigten betrekkelijk het zeewezen (1853), no. 2, pp. 46-86 and pl.; J. Wentholt, Memoriaal reis Admiraal van Wassenaer, s.l. 1869, manuscript in HSM, inv. no. S.2277(01); J.M. Obreen et al., handwritten inventory list for items 944 to 1431, 1884, manuscript in HNA 476 RMA, inv. no. 1089, no. 1060; P.H. van Cittert, ‘Over vochtwegers’, De Natuur (1928), p. 265 and De Natuur (1929), pl. 1

J. van der Vliet, 2016, 'A.P. How, Salinometer, London, 1850 - 1865', in J. van der Vliet and A. Lemmers (eds.), Navy Models in the Rijksmuseum, online coll. cat. Amsterdam: hdl.handle.net/10934/RM0001.COLLECT.244875