BURNING GLASS. PLATE CALL. Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 9 Fig. 10 Fig. 11 Fig. 1. A diagram showing a series of parallel horizontal lines representing light rays entering from the left. These rays pass through a convex lens and converge at a single point on the right, representing the focal point. Fig. 2. A diagram showing parallel horizontal light rays entering from the left. These rays pass through a concave lens and diverge as if they were coming from a point on the left side of the lens, representing the virtual focal point. Fig. 3. A diagram of a circular lens. Parallel light rays from the left converge at a point labeled 'F' on the right. The optical center is labeled 'O'. The distance from the optical center to the focal point is labeled 'f'. Points 'A', 'B', 'C', and 'X' are marked on the lens's circumference. Fig. 4. A diagram showing a lens on the left focusing parallel light rays from the left onto a circular object on the right. The object is labeled with points 'A' and 'B'. Fig. 5. A diagram similar to Fig. 4, but with the lens and object positioned differently. The lens focuses light from the left onto a circular object on the right, labeled with points 'A' and 'B'. Fig. 7. A large, detailed diagram of an optical instrument. It features a large rectangular viewing screen mounted on a horizontal cylindrical base. The base is supported by a three-legged tripod stand. Various adjustment knobs and levers are visible on the top and sides of the instrument. Labels include 'S', 'T', 'V', 'O', 'Q', 'R', 'M', 'N', 'X', 'Y', 'Z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'K', 'L', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'. Fig. 8. A diagram of a mechanical component, possibly a bracket or a part of the instrument's base. It has two vertical adjustment knobs labeled 'S' and 'T' at the top. Below them are several adjustment screws and a central pivot point labeled 'O'. The base is labeled 'V'. Fig. 9. A diagram of a vertical optical element, possibly a lens or a prism. It has a long, narrow shape with multiple focal points or adjustment points labeled along its length: 'G' at the top, followed by 'B', 'A', 'M', 'L', 'O', 'N', 'F', 'K', 'H', 'E' at the bottom. Fig. 11. A diagram of a cross-shaped mechanical component. It has a central horizontal bar with a vertical bar crossing it. There are adjustment knobs and screws at the ends of the arms. Labels include 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'. Fig. 12. A diagram of a square frame. The four corners are labeled with letters: 'A' at the bottom-left, 'B' at the bottom-right, 'C' at the top-right, and 'D' at the top-left. Fig. 6. A diagram of a large, adjustable platform. It has a rectangular base with a grid pattern on top. The platform is supported by a complex metal frame with various adjustment mechanisms, including a large screw and a lever. Labels include 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'. The overall impression is that of a preliminary or working drawing on a historical document. Fig. 1. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 1. Fig. 2. Fig. 3. Fig. 8. Fig. 6. Fig. 5. Fig. 4. Fig. 7. The seal features a laurel wreath surrounding a central sunburst or starburst design. The Latin text "ADVOCATORUM" is arched across the top, and "BIBLIOTHECA" is arched across the bottom, with small dots separating the words.