Books like The Letters to His Friends
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The Letters to His Friends is 391 pages, about 7 hours 10 minutes at 250 words a minute.
12 books to read next
How long each takes
Epistulae Morales 2.3 h 
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The Periodic Table 4.4 h 
The City of God 8.0 h 
April Blood 5.5 h 
De Medicina 9.2 h 
Way to Wealth 39 min 
The Roman Cookery Book 4.3 h 
Cornelius Nepos 4.8 h 
The Ethics 4.9 h G̲h̲ubār-i K̲h̲āt̤ir 7.5 h 
Italian Journey, 1786-1788 9.3 h Bar height shows length. Estimated at 250 words a minute.