Showing 278 items
matching optical
-
Parks Victoria - Point Hicks Lightstation
Weights
A small number of heavy cast iron weights and two rods remain at the Point Hicks Lightstation. These weights comprise one rod with a forked top and four circular weights attached to the bottom of the shaft. The weights and rods were part of the original clockwork mechanism that was fitted beneath the lens to keep the kerosene‐fuelled light turning. They were attached to a cable or chains and moved vertically in similar fashion to the way weights move on grandfather clocks. As the weight fell, the optic clock was driven and the lens was turned. To keep the clock turning, the weight needed to be wound back up to the top of its travel. The cables and weights in this lighthouse were visible as they moved through the length of the tower up to the lantern room. It was usual for systems to move inside a tube extending up to the top, but in this case the tower’s cast iron spiral staircase, which is supported on cantilever cast iron brackets set into the concrete wall, spiralled around the space in which they moved. Lighthouse keepers had the arduous job of having to constantly wind the clock to keep the light active, and at least two keepers needed to observe a strict roster of hours. When electric motors were invented, all of this became redundant and the motors were able to turn the optic for as long as there was power to drive them. In December 1964, the original 1890 Chance Bros kerosene‐fuelled light and clockwork mechanism were replaced by small electric motor, and the number of keepers reduced to two. The six circular weights and rods originate from the obsolete system and may have been part of a larger set. Wilsons Promontory retains seven of its original set of ten weights, all of which are detached from the tower’s weight tube. Cape Schanck has a set of fourteen weights remaining in situ as well as another four detached weights, which have inscriptions. One weight is displayed in the lantern room at Cape Otway. The image shows four of the clockwork weights attached to a rod with a forked top. They were part of the original clockwork mechanism that was fitted beneath the lens to keep the kerosene‐fuelled light turning. The Aldis lamp in its case sits on the floor next to the weights. Source: Parks Victoria.The Point Hicks weights have first level contributory significance for the insights they provide into the superseded technology and operations of a late nineteenth century lighthouse. They are well provenanced and are significant for their historic value as part of the lightstation’s Chance Brothers optical system installed in 1890. Four circular metal weights are stored on a metal rod with a forked section at the top. The weights have a cut out section which allows the weights to be removed easily. -
Parks Victoria - Point Hicks Lightstation
Weights
A small number of heavy cast iron weights and two rods remain at the Point Hicks. The weights and rods were part of the original clockwork mechanism that was fitted beneath the lens to keep the kerosene-fuelled light turning. They were attached to a cable or chains and moved vertically in similar fashion to the way weights move on grandfather clocks. As the weight fell, the optic clock was driven and the lens was turned. To keep the clock turning, the weight needed to be wound back up to the top of its travel. The cables and weights in this lighthouse were visible as they moved through the length of the tower up to the lantern room. It was usual for systems to move inside a tube extending up to the top, but in this case the tower’s cast iron spiral staircase, which is supported on cantilever cast iron brackets set into the concrete wall, spiralled around the space in which they moved. Lighthouse keepers had the arduous job of having to constantly wind the clock to keep the light active, and at least two keepers needed to observe a strict roster of hours. When electric motors were invented, all of this became redundant and the motors were able to turn the optic for as long as there was power to drive them. In December 1964, the original 1890 Chance Bros kerosene-fuelled light and clockwork mechanism were replaced by small electric motor, and the number of keepers reduced to two. The six circular weights and rods originate from the obsolete system and may have been part of a larger set. Wilsons Promontory retains seven of its original set of ten weights, all of which are detached from the tower’s weight tube. Cape Schanck has a set of fourteen weights remaining in situ as well as another four detached weights, which have inscriptions . One weight is displayed in the lantern room at Cape Otway. The Point Hicks weights have first level contributory significance for the insights they provide into the superseded technology and operations of a late nineteenth century lighthouse. They are well provenanced and are significant for their historic value as part of the lightstation’s Chance Brothers optical system installed in 1890.PHLS0005.1 Round cast iron weight with flat base used for lens clock-work mechanism attached to a bent metal rod. PHLS0005.2 Removable round cast iron weight with flat base used for lens clock-work mechanism stored above the other weight. -
Mont De Lancey
Magnifying glass
Belonged to Mrs. Ellen & Mr. Charles CornellSmall brass pocket magnifying glass - brass surround. Round with round finger hold.magnifying glasses, optical instruments -
Mont De Lancey
Magnifying glass
Small brass pocket magnifying glass with glass viewer.magnifying glasses, optical instruments -
The Ed Muirhead Physics Museum
Optical Munitions Test Plates
Associated sheet of paper inside box lists each of the test plates as having been tested and found defective.Cardboard box containing cotton wadding and straw padding layered above glass plates individually wrapped in tissue paper. Five plates in the top layer, followed by more padding, 2 more plates, padding, 8 glass plates, padding and straw. Plates are variously sized and circular in shape.Handwritten on box lid: 'REJECT TEST PLATES / MK1 DIAL SIGHT' unreadable handwritten inscription '18' '[E. E. N Wa...worth] / [...] / [Kob...]' '23/11/45' Munitions labelled with technical specifications of each lens. dial sight, optical munitions, glass, mk 1 -
The Ed Muirhead Physics Museum
Instrument - Becquerel Phosphoroscope (incomplete), c1860-1880
The phosphoroscope was invented by Alexander Edmund Becquerel and used to measure the amount of time that a phosphorescent substance will glow after being irradiated by a brilliant source of light.The phosphoroscope consists of a round metal chamber with a pair of rotating discs inside, arranged so that no light can pass directly through the chamber. The discs have cut-out windows spaced equally at regular angular distances and are turned by the hand crank linked to a gear mechanism. The sample is placed in a specially designed holder into the small opening near the gearing, and it is exposed to the light source through the large rear condensing lens.Engraved on chamber: 'Phosphoroscope de E. Becquerel / J. Duboscq a Parisbecquerel phosphoroscope, phosphoroscope, optical instruments, phosphorescent, alexander edmund becquerel, jules duboscq, france -
The Ed Muirhead Physics Museum
Instrument - Artillery director (No 6 Mk II with tripod), c1924
Possibly related to the range-finding equipment sent from England for dismantling during the 1940s so University of Melbourne Physics staff could develop their own equipment. Related to object 463.2Green painted brass director mounted on a grey metal base plate. Secured to a wooden tripod with coated copper wire cord linking tripod legs.Theodolite body engraved with: the broad arrow on top, and on side with 'DIRECTOR No 6 MK II / COOKE TROUGHTON & SIMMS LTD / 1924 / No 1126'artillery instruments, wwii artillery, no 6 director mk ii, optical equipment, cooke troughton & simms -
Vision Australia
Mixed media - Object, Keeler ophthalmic testing set, unknown
Testing of eye conditions requires the services of eye specialists, who often had to travel around a wide area. This kit is incomplete, but demonstrates how optometrists needed a wide variety of instruments to diagnose sight conditions. Although incomplete, it also contains a booklet for the Standard Testing Set 1H-1 produced by the same company (Keeler) and briefly describes some of the instruments in the case.1 maroon case with two blue velour inserts'Note this side up' in Dymo tape on outside.assessments, keeler optical products