I can report further progress on the location of the Atkinsons’ residence in St Petersburg following their return from Siberia in December 1853. I have now located the actual building, which is still there. The property, known as Dom Gutschow, was originally built for the great German mathematician Leonhard Euler, who was given the money to build it by the Empress Catherine after a fire destroyed the previous building, from which Euler only just escaped with his life. He lived there from 1766-1783 and there is a plaque on the wall to commemorate this fact.
(It is interesting to note that Thomas mentions Euler’s granddaughter in the introduction to his book Oriental and Western Siberia, who he thanks and calls “a worthy descendant of the mathematician”.)
Then in 1851 it was substantially altered and extended by the Saxon merchant Anton Gutschow. Gutschow was active in the flax trade and in various manufacturing businesses and was obviously a very wealthy man. He bought the two properties at the end of the 10th Line on Vassilevsky Island, adding a third floor in 1851 and building a new façade. Presumably Thomas and Lucy rented their property from him, although there is no information at present. Gutschow was well connected with many British merchants, as is clear from a cutting from The Times, located by Sally Hayles.
Later, after the Russian Revolution in 1917, it became a school. Today part of it is occupied by the Institute of Oriental Studies.
You can see the location of the house on the map below:
The waterway to the south is the River Neva. So the house was almost on the main embankment facing the city from the island. Just a few hundred yards to the East on the other bank of the river is the Hermitage Museum and the beginning of Nevsky Prospekt. So the house was very central and rather grand, having only been completed three years before the Atkinsons took up residence.