You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Imperialism

Context:
To better illustrate this idea, Bassett focuses his analysis of the role of nineteenth-century maps during the "scramble for Africa". He states that maps "contributed to empire by promoting, assisting, and legitimizing the extension of French and British power into West Africa". During his analysis of nineteenth-century cartographic techniques, he highlights the use of blank space to denote unknown or unexplored territory. This provided incentives for imperial and colonial powers to obtain "information to fill in blank spaces on contemporary maps".

Question:
What provided an incentive to western empires to colonize Africa?

blank spaces on contemporary maps