Directions:

Crookes' home, the home of his father, Masborough House, on Brook Green - N51 29.72 W0 13.03.
Furnival Gardens, the site of Hatchett's home on Lower Mall where he discovered niobium - N51 29.42 W0 13.99.
"1" = Former site of John Hatchett, where the son Charles (discoverer of niobium) spent some of his years; across the street from Hop Poles Inn (a historic haunt of Hatchett), 17-19 King Street - N51 29.56 W0 13.55.
"2" = Lincoln House, former home of Hutsman Tioxide headquarters, where portrait of Gregor formerly resided, 137-143 Hammersmith - N51 29.64 W0 12.83. [Portrait now resides at Billingham {LINK to billingham030-MVC-391L.JPG}].