English Language · English

Read the passage and answer the question: 'Have you ever been at sea in a dense fog, when it seemed as if a tangible white darkness shut you in, and the great ship, tense and anxious, groped her way toward the shore with plummet and sounding line, and you waited with beating heart for something to happen? I was like that ship before my education began, only I was without compass or sounding-line, and had no way of knowing how near the harbor was. 'Light! Give me light!' was the wordless cry of my soul, and the light of love shone on me in that very hour.' What does the word 'tangible' mean in the given context?