On line 10, the words "Being" and "Author" refer to the same idea and are written as proper nouns. How is the meaning of the word "Author" on line 10 different than how the word author was used in question 4a?

Hello. You did not enter the text to which this question refers, which makes it very difficult to answer it exactly. However, I will try to help you in the best possible way.

As you showed that the word "author" in line 10 was used as a proper noun, we can consider that the same word in line 4 was used in a general way and did not specify an exact person. This is because proper nouns are terms used to specify something or someone, as the question states that the word "author" was not used with the same meaning in line 4, we can consider that this is the difference.

whose power in the senate is equal to the power of the speaker of the house?