4. A LOCATING DEVICE FOR LOCATING A FLAT-SIDED UPRIGHT MEMBER RELATIVE TO A HORIZONTAL MEMBER PRIOR TO THE INTERCONNECTION OF SAID MEMBERS, COMPRISING A GAGE FIXEDLY SUPPORTED ABOVE SAID HORIZONTAL MEMBER, SAID GAGE INCLUDING A GAGE SUPPORT HAVING AN INDICATING ELEMENT DENOTING THE PROPER POSITION OF SAID UPRIGHT MEMBER WITH RESPECT TO A VERTICAL PLANE PERPENDICULAR TO SAID HORIZONTAL MEMBER, A MOVABLE GAGE MEMBER ON SAID GAGE SUPPORT AND BEING ADAPTED TO BE MOVED HORIZONTALLY AND TRANSVERSELY RELATIVE TO SAID INDICATING ELEMENT, A PARALLELISM BLOCK ON SAID GAGE MEMBER, SAID BLOCK HAVING A FLAT SIDE, SAID BLOCK BEING MOVABLE WITH SAID GAGE MEMBER AGAINST A FLAT SIDE OF SAID UPRIGHT MEMBER, MEANS BIASING SAID GAGE MEMBER TRANSVERSELY TO MOVE THE FLAT SIDE OF SAID BLOCK INTO ENGAGEMENT WITH A FLAT SIDE OF SAID UPRIGHT MEMBER, AN INDICATOR ARM ASSOCIATED WITH SAID BLOCK AND EXTENDING HORIZONTALLY AND PERPENDICULAR WITH RESPECT TO THE LINE OF MOVEMENT OF SAID GAGE MEMBER AND INCLUDING