Here is a concise summary of the provided text:
**Title:** Evidence of a Past Warmer Climate and Potential Historical Distortion
**Key Points:**
1. **Buildings suggest a warmer past**: Many pre-19th century palaces and mansions in northern regions have large windows, indicating they were built for a warmer climate.
2. **Late addition of heating systems**: Evidence shows that heating systems were often added to buildings as an afterthought, implying a sudden change in climate.
3. **Thermal vestibules were retrofitted**: Many old buildings have vestibules that were clearly added later, suggesting a response to newly colder conditions.
4. **Lack of waterproofing**: Older buildings often lack waterproofing, which might indicate that freezing temperatures were not initially a concern.
5. **Roof angle changes**: Some buildings have had their roof angles sharpened, possibly to accommodate newfound snow.
6. **Pre-19th century artwork lacks snow**: Engravings and paintings from before the 19th century rarely depict snow, hinting at a warmer climate.
7. **Palm trees in unexpected places**: Historical engravings show palm trees in areas where they cannot currently survive (e.g., Astrakhan, Peterhof), supporting a warmer past climate.
8. **Mammoth presence in the 19th century**: The existence of mammoths in the 19th century, as discussed in a related video, is consistent with a different climate at the time.
9. **Historical events like the "Year Without Summer" (1816)**: Documented unusually cold years and global cooling events may be connected to a broader climate shift.
**Overall Claim:** Historical records and physical evidence suggest that the climate was warmer in the past, and there may have been a catastrophic event leading to a sudden cooling, which historians may have distorted or overlooked.
Here are the key facts extracted from the text, without opinions, with each fact numbered and kept as short sentences:
1. A previous video about 10 buried cities gained 1 million views.
2. Historians often work with written sources from before the 18th century, which can be easily forged.
3. Buildings from before the 19th century were often constructed with large window areas, typical for southern, hot regions.
4. Some buildings in northern territories have window sizes that would be impractical for the local climate.
5. An extension to a palace (housing the famous lyceum where Alexander Pushkin studied) was built in the early 19th century with noticeably smaller window areas.
6. Many buildings initially lacked heating systems, which were later added.
7. Researchers found evidence of stoves being added to buildings after their initial construction.
8. Examples of such additions include churches with hastily added chimneys.
9. Thermal vestibules were often added to buildings, sometimes not matching the original architectural style.
10. Old photographs show some buildings without vestibules, which were added later.
11. The lack of waterproofing in old buildings suggests a different climate at the time of construction.
12. Changes in roof angles in old buildings may indicate a shift from little to more snowfall over time.
13. Engravings and paintings from before the 19th century rarely depict snow.
14. A study analyzed paintings and engravings, finding no winter scenes before the 19th century (link to study in description).
15. Palm trees are depicted in 17th-century engravings of Astrakhan, where they no longer grow naturally.
16. Palm trees are also shown in old images of Peterhof, St. Petersburg.
17. Mammoths, being tropical animals, could not have survived in a climate like today's during winter.
18. A previous video on the channel suggested mammoths lived into the 19th century, implying a different climate.
19. 1816 is known as the "Year Without Summer" due to unusually cold weather in Western Europe and North America.
20. This year remains the coldest on record in the USA, based on early meteorological observations.
21. There are claims of pineapple and other tropical fruits being grown in central Russia in the 18th and 19th centuries, but no documentary evidence was found.