A gaslight is a lamp that produces light by burning gas.
The gaslights in the passage would be on, turned low.
Gaslight is also the light that the lamp produces.
He would show his collection by gaslight.
gaslight in British English
(ˈɡæsˌlaɪt)
noun
1.
a type of lamp in which the illumination is produced by an incandescent mantle heated by a jet of gas
2.
the light produced by such a lamp
verbWord forms: -lights, -lighting, -lighted or -lit
3. (transitive) informal
to attempt to manipulate (a person) by continually presenting them with false information until they doubt their sanity
Derived forms
gaslighting (ˈgasˌlighting)
noun
Word origin
sense 3 from Patrick Hamilton's play Gas Light (1938), in which a husband attempts to drive his wife insane by insisting that thegaslight in their home is not becoming dimmer
gaslight in American English
(ˈgæsˌlaɪt)
noun
1.
the light produced by burning illuminating gas
2.
a gas jet or burner
adjective
3.
of or suggesting the period when gaslight was used for lighting