"on one end a large shining map, marked with all the colours of a rainbow"
Map of Africa colour-coded with European colonial possessions (1904)
Public DomainMap of Africa colour-coded with European colonial possessions (1904) - Credit: American Encyclopedia

Late 19th and early 20th century maps of the world tended to use a colour code to indicate colonial possessions: red for British territories, blue for French, orange for Portuguese, green for Italian, purple for German and yellow for Belgian.

The 'East Coast... where the jolly pioneers of progress drink their jolly lager-beer' refers to the German colony of Deutsch-Ostafrika in East Africa, which included present-day Burundi, Rwanda and Tanganyika (the mainland part of Tanzania). In Blackwood's Magazine (June 1898), Robert C. Witt's article 'An Experiment in Colonization' described a visit to the German colony in East Africa and how German beer 'flowed as it flows in the Hofbräu at Munich on a hot summer's day.'