Ernst Graner was and Austrian painter active in the late 19th and early 20th centuries.
Graner painted genre scenes and landscapes, but is best known for his deftly rendered views of architecture and city scenes, particularly in Vienna.
In the larger images available on the web, you can see that for all the detail and accuracy of his paintings, his approach to watercolor is confidently relaxed and not stiff.
Some of the images I came across seemed overly saturated to me, as is often the case with online images of art from the 19th century and earlier. I’ve tried to select versions here that seem more likely to be true to the originals.