Drawing, photometric arrangement by Fried [Friedrich] Veith Plate 43, figure 4 showing a photometric arrangement of instruments used in Bunsen and Roscoe's experiments, including a blackened tube with a diaphragm of drawing paper, a divided quadrant, a moveable scale, a burner, an eye tube, and a lamp. Inscribed with publication and plate details. Signed bottom right 'Fried. Veith del.' The manuscript for this paper is wanting. Subject: Physics / Chemistry Published in Philosophical Transactions as part of paper titled 'Photo-chemical researches.—Part IV' by Robert Wilhelm Bunsen and Henry Enfield Roscoe. Received and read by the Royal Society on 26 May 1859. [1859]