Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.

Example Input: Passage: The most useful instrument for analyzing the performance of steam engines is the steam engine indicator. Early versions were in use by 1851, but the most successful indicator was developed for the high speed engine inventor and manufacturer Charles Porter by Charles Richard and exhibited at London Exhibition in 1862. The steam engine indicator traces on paper the pressure in the cylinder throughout the cycle, which can be used to spot various problems and calculate developed horsepower. It was routinely used by engineers, mechanics and insurance inspectors. The engine indicator can also be used on internal combustion engines. See image of indicator diagram below (in Types of motor units section). Question: Where was the Charles Porter steam engine indicator shown?
Example Output: London Exhibition

Example Input: Passage: In 1700 several hundred French Huguenots migrated from England to the colony of Virginia, where the English Crown had promised them land grants in Lower Norfolk County. When they arrived, colonial authorities offered them instead land 20 miles above the falls of the James River, at the abandoned Monacan village known as Manakin Town, now in Powhatan County. Some settlers landed in present-day Chesterfield County. On 12 May 1705, the Virginia General Assembly passed an act to naturalise the 148 Huguenots still resident at Manakintown. Of the original 390 settlers in the isolated settlement, many had died; others lived outside town on farms in the English style; and others moved to different areas. Gradually they intermarried with their English neighbors. Through the 18th and 19th centuries, descendants of the French migrated west into the Piedmont, and across the Appalachian Mountains into the West of what became Kentucky, Tennessee, Missouri, and other states. In the Manakintown area, the Huguenot Memorial Bridge across the James River and Huguenot Road were named in their honor, as were many local features, including several schools, including Huguenot High School. Question: When were these settlers naturalized as English colonists?
Example Output: 12 May 1705

Example Input: Passage: Paleoclimatologists measure the ratio of oxygen-18 and oxygen-16 in the shells and skeletons of marine organisms to determine what the climate was like millions of years ago (see oxygen isotope ratio cycle). Seawater molecules that contain the lighter isotope, oxygen-16, evaporate at a slightly faster rate than water molecules containing the 12% heavier oxygen-18; this disparity increases at lower temperatures. During periods of lower global temperatures, snow and rain from that evaporated water tends to be higher in oxygen-16, and the seawater left behind tends to be higher in oxygen-18. Marine organisms then incorporate more oxygen-18 into their skeletons and shells than they would in a warmer climate. Paleoclimatologists also directly measure this ratio in the water molecules of ice core samples that are up to several hundreds of thousands of years old. Question: What group of scientists seek to measure the amounts of oxygen in marine animals?
Example Output:
Paleoclimatologists