REMOVE

1. Spectrum analysis

WHAT

1. Physics (5)
2. Chemistry (3)
3. Astrology (1)
4. Astronomy (1)

WHERE

1. England: Greater Manchest … (5)

WHO

1. Roscoe, Henry E. (Henry E … (2)
2. Abney, William de Wiveles … (1)
3. Huggins, William, Sir, 18 … (1)
4. Lockyer, Norman, Sir, 183 … (1)

WHEN

1. 19th Century CE (5)
2. 1871? (3)
3. 1866-79] (1)
4. 1879 (1)