《明史·志·卷八》
以赤道出地度转减周天的四分之一，余四十度九十四分九十三秒七十五微，就是北京的纬度。
以赤道出地度转减周天四之一，余四十度九十四分九十三秒七十五微，为北京北极出地度。
Subtract one-quarter of the celestial sphere from the equatorial angle to get 40 degrees, 94 minutes, 93 seconds, and 75 microseconds, which is the latitude of Beijing.
<s>[INST] Highlight and translate the key terms in the Classical Chinese text: 以赤道出地度转减周天四之一，余四十度九十四分九十三秒七十五微，为北京北极出地度。, and explain their significance in the context of the passage. [/INST]
**Key terms and their translations**:
- 赤道 (chì dào): equator
- 出地度 (chū dì dù): angle of elevation above the horizon
- 周天 (zhōu tiān): celestial sphere
- 余 (yú): remainder
- 九十四分 (jiǔ shí sì fēn): 94 minutes
- 九十三秒 (jiǔ shí sān miǎo): 93 seconds
- 七十五微 (qī shí wǔ wēi): 75 microseconds
- 北京 (Běi jīng): Beijing
- 北极 (běi jí): North Pole

**Significance in the context**:
This passage is describing the method for calculating the latitude of Beijing. The key terms are used to define the various angles and measurements involved in this calculation.

The first step is to determine the angle of elevation of the equator above the horizon at Beijing. This is done by subtracting one-quarter of the celestial sphere from the equatorial angle. The result is 40 degrees, 94 minutes, 93 seconds, and 75 microseconds.

The next step is to determine the latitude of Beijing. This is done by subtracting the angle of elevation of the equator from 90 degrees. The result is the latitude of Beijing, which is 39 degrees, 54 minutes, 6 seconds, and 25 microseconds.

**Final English translation**:
Subtract one-quarter of the celestial sphere from the equatorial angle to get 40 degrees, 94 minutes, 93 seconds, and 75 microseconds, which is the latitude of Beijing.</s>
Highlight and translate the key terms in the Classical Chinese text: 以赤道出地度转减周天四之一，余四十度九十四分九十三秒七十五微，为北京北极出地度。, and explain their significance in the context of the passage.
user
**Key terms and their translations**:
- 赤道 (chì dào): equator
- 出地度 (chū dì dù): angle of elevation above the horizon
- 周天 (zhōu tiān): celestial sphere
- 余 (yú): remainder
- 九十四分 (jiǔ shí sì fēn): 94 minutes
- 九十三秒 (jiǔ shí sān miǎo): 93 seconds
- 七十五微 (qī shí wǔ wēi): 75 microseconds
- 北京 (Běi jīng): Beijing
- 北极 (běi jí): North Pole

**Significance in the context**:
This passage is describing the method for calculating the latitude of Beijing. The key terms are used to define the various angles and measurements involved in this calculation.

The first step is to determine the angle of elevation of the equator above the horizon at Beijing. This is done by subtracting one-quarter of the celestial sphere from the equatorial angle. The result is 40 degrees, 94 minutes, 93 seconds, and 75 microseconds.

The next step is to determine the latitude of Beijing. This is done by subtracting the angle of elevation of the equator from 90 degrees. The result is the latitude of Beijing, which is 39 degrees, 54 minutes, 6 seconds, and 25 microseconds.

**Final English translation**:
Subtract one-quarter of the celestial sphere from the equatorial angle to get 40 degrees, 94 minutes, 93 seconds, and 75 microseconds, which is the latitude of Beijing.
assistant