Some years ago I linked to the book While Benefit Street was young (1943), and I noted that another book by the same author was not yet online. The other book has now appeared at Archive.org. The Pageant of Benefit Street down through the years (1945) was written by someone who had lived on the street as a child, being then a few years older than Lovecraft.

Lovecraft almost ended up living on that street in 1933, his choice then being between 66 College Street with his aunt or a lone room in the Seagrave Mansion on Benefit Street. An astronomy newspaper column by Lovecraft (Sept 1914) suggests a reason for the second possible choice…

Mr. Seagrave, who is connected with the astronomical department of Harvard University, and who is one of the foremost astronomers of the present time, formerly had an observatory on Benefit Street in this city.

… the implication being that there was still some connection between Seagrave and Lovecraft via astronomy. Frank Evens Seagrave (1860 – August 1934) was still alive at that point and aged 74. Although a letter from Lovecraft, considering his options, implies the old man had by then moved out…

the old Seagrave mansion where the noted astronomer F. E. Seagrave dwelt & had his private observatory until 1914

Given that Lovecraft had the offer of a room there, we might plausibly assume that Mr. Seagrave was letting rooms in his old place to suitably refined but impoverished old gents of Providence. And especially so if they had a connection with Brown or astronomy.