Sentence:  Timothy Palmer , who invented and later patented the arch type of construction for wooden bridges , <WSD>was</WSD> the genius who planned and supervised the building of the Essex , or `` Deer Island '' bridge although the actual work was carried out under the direction of William Coombs , who received 300 as recompense . 
Meaning of the word marked with <WSD> tags:  be identical to; be someone or something