The two advances or technologies that made it possible for Europeans to increase their contacts with the regions and peoples of the interior of Africa were:
1. Railway line
The British built and extended railroads and the telegraph into the interior of Africa to enable the British personnel to survive in the interior of Africa. The railway allowed the British to recruit churches, military, and commercial firms and European staff people to go and reside in the interior of Africa. The railway further helped in the transportation of raw materials to the ports and back to Europe.
2. Advances in the medical field
Advances were made in medical science, more especially in the field of tropical disease, which made it safer for Europeans to go into the interior of Africa, which was prone to tropical diseases.