This plate illustrates various surveying levels and their components, labeled Fig. 1 through Fig. 14: Fig. 1: A long, thin level with a central support and adjustment screws. Fig. 2: A long, thin level with a central support and adjustment screws. Fig. 3: A spirit level with a vertical column and a circular base. Fig. 4: A tall, thin level with a circular base and adjustment screws. Fig. 5: A tall, thin level with a circular base and adjustment screws. Fig. 6: A spirit level with a vertical column and a circular base. Fig. 7: A small, triangular level with a circular base. Fig. 8: Two small, thin levels with circular bases. Fig. 9: A large, thin level with a circular base and adjustment screws. Fig. 10: A small, thin level with a circular base. Fig. 11: A small, thin level with a circular base. Fig. 12: A small, thin level with a circular base. Fig. 13: A large, thin level with a circular base and adjustment screws. Fig. 14: A tall, thin level with a circular base and adjustment screws. Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. A faint architectural drawing of a building facade, possibly a church or cathedral. The drawing shows a central dome on top of a rectangular structure. Below the dome, there are several horizontal levels or tiers, each with different architectural details. The drawing is very light and appears to be a watermark or a faded print. The entire page is covered with numerous brownish stains, likely from water damage or age. Fig. 1. Fig. 1 is a geometric diagram showing a vertical line MM' and a horizontal line NB intersecting at point N. A dashed line m-n passes through N, representing a line of sight. Fig. 2. Fig. 2 is a perspective drawing of a leveling instrument. It consists of a horizontal tube AB mounted on a cylindrical base. The base has a small rectangular window with a viewing vane. The instrument is placed on a flat surface CD. Fig. 3. Fig. 3 is a geometric diagram showing a large inverted triangle with vertex T. A horizontal line AC is drawn through the triangle. A vertical line passes through O and D. A curved line segment connects points on the triangle. A dashed line represents a line of sight. Fig. 4. Fig. 4 is a geometric diagram showing a right-angled triangle ABC with the right angle at B. A curve is drawn from point C to point A, passing through point D. Fig. 4. Fig. 5. PROFILE Fig. 7. CHARLESDARWIN