The technology in Hart's cartoon may be outdated and whimsical to you infidels, but in Islamic lands I assure you based on personal observation, it would, if they had the skill and the will to dig a hole and erect such an imposing structure without relying on guest workers, represent a giant leap forward.
BTW, the use of the modern convenience depicted is also quite impossible if one is to follow the explicit directions in the Q'uran (note pc spelling) for handling the excretory functions of the faithful.