The Trousset encyclopedia

The “Nouveau dictionnaire encyclopédique universel illustré“, to give it its full and original name, was published in Paris between 1886 and 1891, under the direction of Jules Trousset. It is said to be complete in six volumes, although a seventh one was released later as an update. The sixth volume is made of maps and charts. These books are in quarto format, approximately 25×35 cm and contain some 800 pages each, except for the smaller sixth one.
Typically following the eighteenth century humanist tradition, which saw the edition of the encyclopedia by Diderot and d’Alembert, it combines lexicographical endeavour with extended information on technical subjects. A particular emphasis was placed on chemistry and electricity, which were at the time fields of recent discoveries, as well as on legal matters. It contains numerous illustrations (over 3000) and in this area, the publishers certainly seem to have pulled all the strings : the wood engravings could be made from photographs as well as from other engravings, taken from technical books, or even encyclopedias published in France or abroad. Very few, if any, must have been made from original designs.
It is easy to imagine, behind this wealth of illustrations, one or more semi-industrial engraving workshops, such as the one kept by the magazine “L’Illustration”, where images where produced around the clock.
Wood engraving was at the time a popular reproduction technique, used in mass publication. As in many books made in the late nineteenth century, the paper has turned yellowish and become very fragile, due to acidity, but it hardly shows any brownish stains.
Most of it is available on Gallica, the site of the french national library, as a series of six files which can be downloaded either in the pdf or in the tiff format. These files are in image mode, not text and over 100 MB each. At this time, the second volume is missing.
Finally, it should be said that its interest nowadays is mainly historical; if you are looking for accurate, up to date information, you’ll probably be better off referring to the Encyclopædia Britannica, or even Wikipedia…