We don't know who the photographer is. In fact, it is probable that there are several photographers in this vintage album of Rome. It is not uncommon on those days to make an album as a collection of pictures rather than an album by a specific photographer.
Rome had become the centre of a large tourism industry due to its historical importance. The city was able to support almost 750 photographers who made, at least, part of their living by selling views of the city to the visitors between 1840 and 1915.