This pH meter was made in 1946 by Cambridge Scientific Instrument Co. Ltd. in London. The company was founded in 1881 and the owner eventually became Horace Darwin, the youngest son of the famous scientist Charles Darwin. It is a portable version that can be used on-site in many different situations. A similar instrument was used by the Chemistry Department of what is now the University of Cambridge. The science of pH measurement began in the 1910s and was further developed in 1926. The pH meter is an electronic scientific instrument used to determine the pH measurements of a solution accurately; the amount of acid and alkaline in it This measurement can have many other applications helping to maintain the appropriate balance for a particular result. For example, it can measure the pH of pharmaceutical medications, soil, swimming pool water and hair shampoos. This Cambridge portable electronic pH instrument was made in 1946 by a company specialising in scientific instruments. It is an early example of much smaller devices used today in many different fields including medicine, and the preservation and conservation of shipwreck artefacts. Flagstaff Hill Maritime Museum and Village's Curator uses a pH meter today in the conservation process of a historic cannon that was recovered from the 1839 wreck of the vessel 'Children'.Scientific instrument, electric Cambridge Portable pH Meter in a polished wooden box with compartments, fold-out doors, and leather carry handle. Includes blue covered Instruction manual with a 'Certificate of Test' inside, and chemicals. Electrodes mounted in compartment. The lid is separate from the base, attached by pins and hinges. A plate inside the lid gives instructions for 'Preparation for Use'. Made by the Cambridge Instrument Company, London, in 1946.Printed on plate: "Cambridge Instrument Co. Ltd, 13 Grosvenor Place, London, S.W.1' Certificate dated: "6-3- 46" (1946)flagstaff hill, warrnambool, maritime museum, maritime village, great ocean road, shipwreck coast, ph meter, cambridge scientific instrument co. ltd, horace darwin, cambridge university, ph balance, scientific instrument, ph measurement

Cambridge Instrument Co Ltd, England operated from 1924 to 1967. They were makers of measuring instruments (electrical) and scientific instruments.Timber framed electrical instrument with interior metal conductor. Brass knobs that screw are at one end labelled 1.5 volts and 15 amps. Plates each end labelledscientific instrument, cambridge instruments, electricity, scientific objects, scientific instruments

450 OHM Galvanometer. Black metal case with levelling feet. Clamps and zero adjustment on top. Two terminal posts.scientific instruments, galvonometer, cambridge instrument co. ltd

Potentiometer Volt Box, 6 ranges: 1.5, 15, 30, 150. Black terminal panel on top of polished wood box. Large circular ventilation holes in all six sides. Distributed by A.E. Supplies Pty Ltd., Melbourne. scientific instruments, potentiometer volt box, cambridge instrument co. ltd, volt box

A type of instrument used in the 1900s to measure very low currents by sending beams of light to the mirror and reflecting this back onto a wall using the mirror as an amplifier. Small currents in V/A can display a displacement of a few inches on the wall. This instrument has to be balanced, hence the air bubble level and adjustable feet. The meter was scaled in degrees. Galvonometer with all brass body shell removable for initital adjustments. Two observation ports. Base with levelling feet.scientific instrument, galvonometer

Horace Darwin, youngest surviving son of Charles Darwin, was a founding partner of the Cambridge Scientific Instrument Company in 1881 (http://www.museumoftechnology.com/cic.html).Composite object with three feet supporting two squared cylinders attached to a clamping device and metal block with four current terminals. Cylinders are covered with red leather. Metal block and clamp base appear painted.Engraved on terminal block: 'No 15548 / THE CAMBRIDGE SCIENTIFIC INSTRUMENT CO LTD. CAMBRIDGE. ENGLAND' Engraved on side of terminal block: 'To be excited from 200 volts circuit / with coils in series. Connect terminals 2 & 3.'cambridge scientific instrument company, electro magnet, electrical equipment, electrical instrumentation

E. R. Watts and Son, makers of theodolites and other surveying instruments, of 123 Camberwell Road, London. The company was established in 1856 by Edwin Watts at twenty-three he had saved £100 from his earnings to start the business with his staff consisting of one boy and later Alexander Clarkson as an apprentice with the workshop a small room over a Bemondsey stable. Watts' first order was from Negretti and Zambra for a mining dial Alexander Clarkson In the early days the firm worked mainly on marine compasses. Edwin Watts would go down to the Docks to adjust the compasses once they had been installed on the ships. In May 1873 the business moved to larger premises a house with a garden. The workshop was also the home of Mr and Mrs Watts and their five sons and three daughters. By now there were fifteen to twenty men employed by the firm. The company were commissioned to supply the Theodolites and Levels for the construction to the Canadian Pacific Railway in 1881. Towards the end of the century, the firm began to make heliographs continuing to produce them for the government until just before the Second World War when by agreement assigned their manufacture to another firm. 1904 The first dividing engine was completed by George William Watts. It was so remarkable an instrument at the time and for years afterwards, In 1907 Arthur Ames went to Canada and started an organisation in Winnipeg in 1909 this became a separate company called E. R. Watts and Son Ltd. of Ottawa. This firm developed considerably and was eventually with the co-operation of three other instrument companies (Cambridge Instrument Co, Ross, and Negretti and Zambra), were reconstituted as ”Instruments Ltd” of Ottawa and Toronto. During the next ten years, the firm expanded greatly to include glass grinding, leather work, dividing and engraving, testing, adjusting and packing. This expansion was continued during the First World War when workshops were completed and the machinery installed and running within eleven weeks from the start of construction. During the war, a Sergeant Coles, among the rats, lice and mud of the trenches, fitted various bits of scrap into his cocoa tin and made the first Flash Spotter for plotting the positions of enemy guns. Coles was rushed home to the firm's factory where he and George William Watts designed a spotter not made out of a cocoa tin and as a result, the Watts Vertical Force Variometer was developed during WWI. Other Watts instruments made in the First World War included the Light Mountain Theodolites which were taken on Mt Everest expeditions. In 1919 ER Watts and Sons was incorporated as a limited company and in 1939 G. A. Whipple joined the Board of Directors. Shortly afterwards, Frank Charles Watts died having been Chairman of the firm for over 37 years and seen it through the First World War with all its expansions and difficulties. He was succeeded by his brother George William Watts with the vacant post of Managing Director being filled by G. A. Whipple. During the Second World War, the company expanded further and the number of employees rose to well over 1,300. In 1946 Watts acquired 78% of Adam Hilger and the microscope maker James Swift and Son Who were Manufacturers of Theodolites, Levels, Alidades, Meteorological Instruments, Variometers, and many other types of scientific instruments Then in 1948 the company amalgamated with Adam Hilger as Hilger and Watts which was then incorporated as a public company.Naval Rangefinder with a vertical wooden handle, and an arrangement of optical lenses. Three reversible brass inserts calibrated on both sides in yards, correspond to various base heights, (20 and 25 feet, 30 and 35 feet and 40 and 50 feet). They are fitted along the axis of the instrument. When the scale for the appropriate base height is selected and inserted, the carriage can be slid for coincidence and the distance read at the index mark on the sliding carriage.inscribed "Rangefinder Cotton Type Mk II" Calibrated scale up to 5000 yds (50 ft), 5000 yds (35 ft), 4000 yds (25 ft) made by E. R. Watts & Son.flagstaff hill, warrnambool, shipwrecked coast, flagstaff hill maritime museum, maritime museum, shipwreck coast, flagstaff hill maritime village, great ocean road, rangefinder, cotton type, e r watts & sons, naval range finder, marine equipment