and standards, as paintings of domestic scenes have sometimes been used as sources for what people ate. But it is far better to go directly to the actual statistics of wage rates and to social investigations for the first topic, and to household accounts, statistics of retail sales and so on for the latter one. A painting of eighteenth-century French peasants consuming bread, garlic and wine may be evidence of their regular diet, but there is always the quite strong possibility that the artist might have been more concerned with infusing his painting with the religious symbolism of the Last Supper than with accurate sociological observation. It is perfectly legitimate for editors and publishers to wish to brighten up articles and books by including reproductions of various works of art. But, with rare exceptions, such art works will, at best, be no more than illustrations; at worst they may have little real relevance to what is being said in the article or book. Serious historians should only use such reproductions as genuine primary sources, explicating them in exactly the same way as they would explicate an extract from a written primary source. 10. Strategy and Structure I have already mentioned the need for identifying a research strategy , using the secondary sources to identify the topics to be addressed and the archives to be used. The writing of history is an iterative process: frequently in writing up one's researches, one will encounter problems necessitating further research in the primary sources,