{"product_id":"vintage-wilson-warden-hair-hygrograph-humidity-measuring-tool","title":"Vintage Wilson Warden Hair Hygrograph Humidity Measuring Tool","description":"\u003ch1\u003eVintage Wilson Warden Hair Hygrograph Humidity Measuring Tool\u003c\/h1\u003e\n\u003cp\u003eThis is a very nice, small bench top, Vintage Wilson Warden Hair Hygrograph Humidity Measuring Tool in a black cast casing with laquered brass drum and internal base. It dates to approximately 1920-1940. \u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003eIn pretty good condition, with a few surface scuffs and scratches in the paintwork commensurate with age and use. \u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eThe black paintwork has faded with age. \u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eIt will need chart paper and a pen. \u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eThe brass \u003cem\u003eWilson, Warden \u0026amp; Co\u003c\/em\u003e label, which would have been attached to the inner base, is missing. \u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e\u003cmeta charset=\"utf-8\"\u003eThe timer movement works well, ticking and keeping time satisfactorily. \u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eI’m not sure how accurate the hygrograph is at measuring the humidity.\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eWilson Warden is Stamped in the base\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003eIt was previously owned by the A.W.E (UK Atomic Weapons Establishment) Electrical Standards Department.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaximum Approximate Size (WHD)\u003c\/strong\u003e: 29 x  18 x 23 cm\u003c\/p\u003e\n\u003cp\u003eA hair hygrograph is a chart recorder which records the humidity (or dew point) over time. It works by using the principle that a human or horse hair changes length depending on the level of humidity in the air.\u003c\/p\u003e\n\u003cp\u003eThe difference in hair length is only 2.5% between humidities of 0-100%. A hair hygrograph is, therefore, a very sensitive piece of equipment! On this instrument the ‘hair’ is located in the open chimney at the side of the recorder. The contraction and expansion of the hair is conveyed to the recorder arm, which charts the readings over time.\u003c\/p\u003e\n\u003cp\u003eAll in all this represents a scarce opportunity to obtain one of these instruments for use or to add to your collection. Please click on the following link for more \u003ca href=\"https:\/\/mullardantiques.co.uk\/collections\/meteorological-weather\" target=\"_blank\"\u003emeteorological and weather instruments.\u003c\/a\u003e\u003c\/p\u003e\n\u003cdiv class=\"contentHeader\"\u003e\n\u003cp id=\"firstHeading\"\u003e\u003cstrong\u003eWilson, Warden and Co\u003c\/strong\u003e were based at Goswell Road, London and, according to 'Grace's Guide' list of exhibitors at the 1929 British Industries Fair were: \u003cmeta charset=\"utf-8\"\u003e\u003cem\u003eManufacturers of Aneroid Barometers (Pendant, Nautical and Surveying types). Barographs, Thermographs, Hydrographs, Recording, and Scientific Instruments. Wood Cases for Timepieces, Grandfather and Grandmother, chiming and striking clocks of every description\u003c\/em\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cspan style=\"border-top-left-radius: 2px; border-top-right-radius: 2px; border-bottom-right-radius: 2px; border-bottom-left-radius: 2px; text-indent: 20px; width: auto; padding: 0px 4px 0px 0px; text-align: center; font-style: normal; font-variant-caps: normal; font-weight: bold; font-stretch: normal; font-size: 11px; line-height: 20px; font-family: 'Helvetica Neue', Helvetica, sans-serif; color: #ffffff; background-image: url(data:image\/svg+xml; base64,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); 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background-size: 14px 14px; background-color: #bd081c; position: absolute; opacity: 1; z-index: 8675309; display: none; cursor: pointer; border: none; -webkit-font-smoothing: antialiased; background-position: 3px 50%; background-repeat: no-repeat no-repeat;\"\u003eSave\u003c\/span\u003e\u003c\/p\u003e","brand":"Wilson, Warden \u0026 Co","offers":[{"title":"Default Title","offer_id":43784530854145,"sku":"","price":0.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0303\/5122\/8972\/products\/Vintage_Wilson_Warden_Hair_Hygrograph_Humidity_Measuring_Tool.jpg?v=1748955535","url":"https:\/\/mullardantiques.co.uk\/en-us\/products\/vintage-wilson-warden-hair-hygrograph-humidity-measuring-tool","provider":"Mullard Antiques and Collectibles","version":"1.0","type":"link"}