Admiralty Pattern 574 Non-Break Guidor Hydrometer
This instrument is supplied in the original admiralty issue case which is dated 1945/6. The item was manufactured by G H Collie & Co. Birkenhead and carries a patent number 2655. It is unusual in that the hydrometer is protected within a glass tube and surrounded by rubber rings to prevent breakage in service use. This is the first example we have seen and despite being over 60 years old, it has survived in near perfect condition.