A 1922 guide, Sex: Avoided Subjects Discussed in Plain English, by Henry Stanton, is one of the most popular downloads from Project Gutenberg, home of 100 000 free books and the first of its kind.

Henry, innocent of Sigmund Freud, writes: "Girls marry, in the final analysis, because love for the male is an innate natural principle of the female nature." And "The natural instinct of a man is to seek his mate. On her he depends for an orderly and lawful indulgence of his sex demands."

A poker-faced comic, Harry is much concerned with adolescents' "self-pollution". He advises fathers to encourage their sons to love "healthy sport in open air".

Harry gets tougher on suspected self-polluting girls: "The bedclothes should be quickly and suddenly thrown off under some pretence."

Sniggering at past generations, a supreme vulgarity, is not the sole impulse behind book downloads.

Popular downloads from Gutenberg include English classics, surgery manuals and travel. And the site, staffed by volunteers, offers the opportunity to quickly create a well-stocked library by downloading 17 000 books at once.

Downloaded books offer several advantages. Because most are out of copyright, they are free and they are easier to read in bed than the weighty traditional object.

Have you noticed how big today's books are? Blame weight on length, and length on what are misnamed word-processors, meaning word-spawners. Today little writing is subject to muscular limits - writer's cramp is all but obsolete. The word-processor is a boon to the verbose and meandering.

(Technology similarly affected films: old technology limited them to 90 minutes in length, roughly the endurance of the average audience member's bladder. The effect of new technology has been to invert Le Corbusier's dictum: today "More is less.")

The word-processor has transferred muscular effort and strain from writer to reader, just as technology has transferred the burden of service (and cost) from provider to buyer. Reading any book longer than 300 pages in bed is a test of brute strength and the first person to devise a ceiling mounted hoist for night readers will have my vote.

This is why downloaded books are manageable. You save them on the disk, print out maybe 50 pages - with the print size that suits you. You print on the reverse side the next day. If you are a collector, you keep a digital library.

This approach obviates reading on a screen or mismatches of scale involved in reading War and Peace on a palm-sized lozenge of an eBook reader.

Computer screens aren't for reading but for scanning, which is a functional act of quickly grasping sense while reading involves the interplay of sense, sound, cadence and look, the inner ear, eye and imagination. And worst, you can't scribble "Rubbish!" on a computer screen. The computer deters critical reading.

Downloaded books are limited. Because most are out of copyright they are older so you don't find Danielle Steel or modern or future classics among downloads.

And until, as they should, writers get a royalty for every download, that's how it should be. Since few countries even pay writers for library borrowings, this will remain.

The second problem is fetishism, which involves reverence for books as objects.

Book fetishists thus wince at images of book-burnings by Nazis but merely shake their head at the burning of human beings.

Today, accumulating books is fast becoming irrational and also ecologically insensitive. Digitised books strike against fetishists with their "But I loved it as a child" (answer: "Show me your teddies"); "I may need something in it"; and, most inanely, "Books do make a room look so warm".