FACTS:

Aldabas  sold  to  Aguirre  a  steel  tank  but  the  latter  wasn't  able  to  take possession.    Then  the  steel  tank  was  sold  by  Aguirre  to  Gabriel  who subsequently sold it to Leonora and Company and eventually was sold to NASSO.    Aguirre  notified  NASSO  of  its  claim  of  ownership  and  thus,  it withheld payment to Leonora.  In both actions, Aguirre was held to be the owner and entitled to P900.
 

HELD:

There is accession by specification.  Aguirre should reimburse Leonora for being a builder in good faith.