Sentence:  It is true, that no diligence can <WSD>aſcertain</WSD> ſucceſs ; death may intercept the ſwifteſt career ; but he who is cut off in the execution of an honeſt undertaking, has at leaſt the honour of falling in his rank, and has fought the battle, though he miſſed the victory. 
Meaning of the word marked with <WSD> tags:  To ensure or effect.