Sentence:  [W]e can't without wonder remember that horrid Invention projected in this place, but thanks be to God diſappointed, wherein there was not Reverence to the ſacred Bones of Princes, but all were <WSD>at one blaſt</WSD> to be offer'd up to "Moloch". 
Meaning of the word marked with <WSD> tags:  At once, at the same moment in time. (from 1379)