Sentence:  "Love" is the weight and motor of the ſoule, the "Spring" that ſets all the wheeles on worke. It is vehement, active, induſtrious, <WSD>unwearied</WSD>, invincible affection; if rightly placed on worthy objects, it workes wonders. 
Meaning of the word marked with <WSD> tags:  Not stopping; persistent, relentless.