Discovery and inspection powers for tax authorities enable compelled attendance, document production, and limited impoundment. Section 246 grants specified income-tax authorities court-like powers for tax purposes, including discovery and inspection, enforcing attendance and oath-examination, compelling production of books and documents, and issuing commissions. Designated officers may exercise these powers for inquiries or investigations even in the absence of pending proceedings, and may impound produced books or documents subject to rules; reasons for impounding must be recorded and retention generally limited to fifteen days unless extended with prior approving authority sanction.