I learned recently that the Principia was once located on Page Avenue in the Hamilton Heights neighborhood, so I went and checked out the couple of remaining buildings from that era of occupation.
On the northwest corner of the site, at Minerva and Montclair, there is this impressive building, which might have been a gymnasium or physical plant building. Previously in 1909, according to fire insurance maps, there was a wood frame gym in approximately the same location.
It is now an apartment building.
Further east down Minerva is this little cottage which was perhaps a dormitory or groundskeeper’s cottage. I am not sure if it is occupied, as it looks like it is boarded up.
The vast majority of the site is now taken up by the Bayer YMCA.
As you can see, there is some of the original wall around the complex surviving.
The star of the site is the former Fourth Church of Christ, Scientist, designed by famed St. Louis architect Albert B. Groves. It is now Solomon’s Temple Church.
I looked at this stretch of Page Avenue before, which is lined with beautiful houses, but sadly is dealing with abandonment and disinvestment. Note the house on the right with the false third floor windows.