Kenneth G. Wilson (1923). The Columbia Guide to Standard American English. 1993.
ABSOLUTE CONSTRUCTIONS, ABSOLUTE PHRASES
The absolute constructions that cause most concern are participial phrases not directly connected to the rest of their sentences. The subject of the participial phrase (train) in the following sentence is not the same as the subject of the main clause (he): The train moving away, he had to run to catch it. If the subject of the participial phrase is unexpressed and differs from that of the main clause, the construction is a dangling modifier: Running to catch the train, it pulled away from him. Absolute constructions that dont dangle are usually Standard (Its whistle blowing, the train began to move). See also ABLATIVE (2); DANGLING MODIFIERS.