Vintage work crew photos

[neilbourjaily]

re post *2441
Rather safe assumption regarding that encased laboratory scale is by Henry Troemner Co. of Philadelphia, PA. A long association between that company and US Government purchasing agents. Used examples still abound, and sell for respectable amounts.
Is the apparatus on left related to the illustration "Surface Welding Apparatus" above their heads to the right? The photos appear to show ideal, acceptable and reject product.
Which fits what the woman standing is doing, that box is surely a lapping turntable.

They're the balance we used in the lab decades ago before digital. Remarkably sensitive. We used tweezers to set the weights because our hand oils would change them, adding weight initially and corroding them eventually.