I inherited a set of Chambers Encyclopedia published in 1890. It provides a fascinating overview of the state of knowledge as it then was, and of the priorities that were thought to matter. Thus there are erudite articles on chemistry and industrial processes and many more discussing the history and politics of pre-WWI Europe. Articles on such matters as Flight and Petroleum are interesting in the light of subsequent discoveries.

So it's a historical document, but not without its uses, and still more convincing on many subjects than its modern equivalents. It's also great for random browsing.

I don't see how a non-printed encyclopedia could ever provide an equivalent snapshot of the state of knowledge at a given date - which may well be to the loss of future generations.

I think you raise a very good point.

Just because something is "out-of-date" relative to "now" doesn't mean it's not at least still interesting, and potentially very valuable and informative from a historical perspective.

Some years ago I did some work on document classification, using Dewey Decimal as the system.

What was interesting was how the classifications have been revised - some 23 times - since the first edition, to both reflect what knowledge was thought important at the time, and changes in the way the knowledge is 'described' - eg, compare some of the original classifications from 1876 with those from the 22nd edition from 2003:

1876:                                 2003:

320   Political Science.               320 Political science
321   Patriarchal Institutions.        321 Systems of governments & states
322   Feudal Institutions.             322 Relation of state to organized groups
323   Monarchic Institutions.          323 Civil & political rights
324   Republican Institutions.         324 The political process
325   Colonies and Emigration.         325 International migration & colonization
326   Slavery.                         326 Slavery & emancipation
327   Foreign and Domestic relations.  327 International relations
328   Legislative annals.              328 The legislative process
329   Political essays and speeches.   329 [Unassigned]

640   Domestic Economy                 640 Home & family management
641   Cookery.                         641 Food & drink 
642   Confectionery.                   642 Meals & table service
643   Food and dining.                 643 Housing & household equipment
644   Fuel and lights.                 644 Household utilities
645   Furniture.                       645 Household furnishings
646   Clothing and toilet.             646 Sewing, clothing & personal living
647   Servants.                        647 Management of public households
648   Laundry.                         648 Housekeeping
649   Nursery and sick-room.           649 Child rearing & home care of persons

680   Mechanic Trades.                 680 Manufacture for specific uses
681   Watch and instrument-making.     681 Precision instruments & other devices
682   Blacksmithing.                   682 Small forge work (Blacksmithing)
683   Lock and gun-making.             683 Hardware & household appliances
684   Carriage and cabinet-making.     684 Furnishings & home workshops
685   Saddlery and shoe-making.        685 Leather, fur goods & related products
686   Book-binding.                    686 Printing & related activities
687   Clothes-making.                  687 Clothing & accessories
688                                    688 Other final products & packaging
689   Other.                           689 [Unassigned]  

So, whilst we wouldn't use the 1876 classification now - now least because any new fields of knowledge after then (such as computing) don't exist in it - it's a fascinating and detailed snapshot of knowledge at that time.

It's not unlike comparing old(er) with new(er) maps.