Before Hong Kong became a skyscraper city, the dozens of "ladder streets" were clearly visible.

A few years before the beginning of World War Two, when the great ocean liners regularly visited the British Crown Colony crammed with rich tourists, a delightful travel book appeared that was entitled simply Hong Kong.

It was written by Ellen Thorbecke and illustrated by Friedrich Schiff. They had previously collaborated in 1934 on Peking Studies, a light-hearted, informative and amusing book. It is a very large volume. Their Hong Kong guide is of a more manageable size.

They produced a number of picture books at the time, including another guidebook of a similar style and format entitled Shanghai. It was published in 1938, the year that city was occupied by the Japanese. Consequently it is a very a rare book.

Today Schiff's drawings are very popular, and collectors are willing to pay thousands of dollars for some of his books. Friedrich Schiff was an Austrian artist, prolific illustrator and cartoonist whose work appeared in newspapers, magazines, books and advertisements throughout China and the Far East.

His collaborator, Ellen Thorbecke, was a distinguished German photojournalist whose maiden name was Ellen Catleen. She was one of the two most outstanding European women photographers working in China in the 1930s, the other being Hedda Morrison. Both women used square format Rolleiflex cameras.

At the time, the traditional way of composing pictures was snapping what you saw through the viewfinder, but Ellen created her style by cropping her prints in unusual ways. In the Shanghai book, she took a rather ordinary view of Jessfield Park and then got Schiff to tart it up by painting jolly little cartoon figures on the print. This horrified the purists.

Her work seems to have irritated the sort of art critics that like to put creative people into neat little boxes. After she married the Netherlands Minister in China, she dropped her maiden name and used Thorbecke instead. This may be why bewildered critics have classified her as an "amateur Dutch photographer" although of course there is nothing remotely unprofessional about her work, which is brilliant, but madly unconventional.

The Hong Kong book is quite difficult to put in a little box because it is not a typical travel guide. It is a potpourri of little one-page essays, photographs and delightful cartoons. Rather than including a list of restaurants, Thorbecke tells you how to behave at a formal Chinese dinner "which offers generous opportunities to Westerners to commit a series of most embarrassing faux pas."

Schiff's beautiful illustration of a "ladder street" could almost have been painted today. Thorbecke explains, "Just as in China proper, the Chinese merchants of the same trade congregate in the same street." This still happens in today's Hong Kong. Hollywood Road is the modern "Curio-shops Street" and there is also still a "Wedding Card Street", although developers want to demolish it and replace the card shops with boring supermarkets.

The idea of producing a crazy Art Nouveau style travel book may seem a rather eccentric concept for a port like Hong Kong in the 1930s, but the book targeted the rich liner passengers who had already been seduced by the stylish travel posters of Cunard and other luxury shipping lines that catered for the class of people who read lifestyle magazines like The New Yorker, Vogue, Vanity Fair and Harper's Bazaar. Schiff's exciting page designs and Thorbecke's writing follow the style of these great magazines.

Thorbecke's work may be overshadowed by Schiff's artistic talent, but it is interesting to note that there are discriminating collectors who are prepared to pay large amounts of money for her extremely rare book of so-called serious photographs, People in China, which she published in London in 1935. Recently, exhibitions of her work have been shown in Dutch museums.