Abney, William de Wiveleslie

1843 - Born on the 24th of July in Derby, England.

1861 - He attended the Royal Military Academy and joined the Royal Engineers.
     
       - He was a pioneer of several technical aspects of photography.
    
       - He became a chemical assistant at the Chatham School of Military Engineering.

1874 - He developed a dry photographic emulsion, which replaced "wet" emulsions.

       - He used this emulsion in an Egyptian expedition to photograph the transit
           of Venus across the sun.

1880 - He introduced hydroquinone.

1882 - He introduced new and useful types of photographic paper, including a formula for
           gelatin silver chloride paper.

1887 - He was also a pioneer in photographing the infrared solar spectrum, as well as researching
           sunlight in the medium of the atmosphere.

       - He invented the "Abney Level", a combined clinometer and Spirit level , used by surveyors
           to measure slopes and angles.

1920 - He died on the 3rd of December in Folkestone, England.