In Silas Mariner by George Eliot, how many sons does Squire Cass have?

Squire Cass has four sons. 

Although the sons are mentioned here and there in the text as "the second son" and "the third son" and so on, if you turn to Chapter 9 in your book, you'll see where the Squire refers to all four of them together:

"Fooleries! Pshaw! it's time you'd done with fooleries. And I'd have you know, sir, you must ha' done with 'em," said the Squire, frowning and casting an...

Squire Cass has four sons. 

Although the sons are mentioned here and there in the text as "the second son" and "the third son" and so on, if you turn to Chapter 9 in your book, you'll see where the Squire refers to all four of them together:

"Fooleries! Pshaw! it's time you'd done with fooleries. And I'd have you know, sir, you must ha' done with 'em," said the Squire, frowning and casting an angry glance at his son. "Your goings-on are not what I shall find money for any longer. There's my grandfather had his stables full o' horses, and kept a good house, too, and in worse times, by what I can make out; and so might I, if I hadn't four good-for-nothing fellows to hang on me like horse-leeches. I've been too good a father to you all—that's what it is. But I shall pull up, sir."

Only two of the Squire's sons are truly important in the story:

1. Godfrey, the oldest, who spends much of the story feeling guilty over not being a proper father to Eppie.

2. Dunstan, the second oldest, whose nickname is Dunsey and who is basically a villain in the story.

We know very little about the other sons:

3. Bob is the third oldest. All we really know about him is that he has long legs and is described as "lithe," and his brothers assume he is the favorite of his father.

4. As for the fourth son, we know nothing about him, not even his name.