Reading lens reflections to determine type.

I am still not clear how to read some lens reflections. I purchased a no-name brass lens from circa 1900. When I shine a light on a group (half the lens) I see one large bright reflection and one much smaller bright reflection. Does anyone know how to interpret this? Thanks.

Probably easier to partially disassemble the lens to see what the configuration is. I.e. if it has a cemented doublet and an airspaced pair then it's a petzval (I think) etc etc..