This review is from: Fra Mauro's Map of the World (Terrarum Orbis)
This product consists of two parts: a CD-ROM that contains a high-resolution scan of the famous Fra Mauro Map, and a huge book that contains transcripts of the labels on the map, their English translations with comments, and a couple hundred pages worth of articles about the various aspects of the map.
This map, created by the Venetian monk Fra Mauro ("Brother Mauro") ca. 1450 is, of course, famous, being perhaps the best example of the European map-making on the cusp of the Age of Discovery. A copy of this map was actually made for the Portuguese king of the day, so you could imagine Bartolomeo Dias and Vasco da Gama studying it in preparation for their pioneering voyages to[ward] Asia; Columbus may have looked at some similar map, wondering how far its western end really was from its eastern end.
Basically, it may be viewed as the last great maps created before two great revolutions - one in maritime technologies, allowing the Europeans to sail all over the world, and the other in book reproduction (the [re-]invention of printing in Europe) - revolutionized European cartography and led to the appearance of works by Mercator, Ortelius, etc. in the 16th century.
Fra Mauro's map is famous, in particular, because it appears contains a lot of geographic information that is (more or less) correct (i.e., not entirely fantastic), but about whose provenance we don't know anything. That is, the good Brother Mauro must have gotten it *somewhere*... but whatever his sources were, they just have not survived to our day. As one example, it shows a fairly reasonably-looking continent of Africa, one you can sail around, even with a Madagascar of sorts (called "Diab") south-east of it... all this a generation before Dias and da Gama.
Now, what do this book and CD give you? There is actually a small printed map coming in a pocket with the book, but since the original map was *huge*, you can't read much of anything on that small map, beyond the names of countries and major regions. The CD has of course high-resolution data - much better than a freely downloadable scan file available e.g. via Wikimedia Commons. But the data are not in some standard portable format such as JPEG or PDF; rather, they are only readable by some specialized program, for the Microsoft Windows operating system, included on the disk. So this is rather inconvenient, if you are used to view images in some general-purpose image file viewer. For example, the program's interface allows you to scroll through the image, or to zoom in on a small piece of it, but you can't zoom out - which means that you can't see more than a very small part of the entire map on the screen at once (unless, that is, you have a really huge screen, or can control your monitor's resolution to be 10,000 by 10,000 or something...) The "transcription" feature, however, is quite convenient: you can click on any text on the map (label, caption) and to see the transcription of the Italian original, or its English translation, as plain text in a pop-up window. A great help for someone not too comfortable with Mediaeval handwriting. (Although I'd say that the text on the map is fairly legible as it is).
The luxuriously printed book itself is... useful, although one wonders if the publisher could come up with a more compact format for what is, basically, a huge dictionary of transcribed and translated map labels, which now happens to be formatted so that most of the pages are 80% blank space. (This is why the thing probably weighs 5 pounds if not more).
The articles, written mostly by the curator of the maps at the Venetian Library, with a contribution from an art historian, are certainly very valuable for anyone interested in the "life story" of this particular map, and in Mediaeval cartography in general. The author tries to probe the problem of "missing sources", and come up with interesting ideas here and there. (Arab manuscripts; interviewing visiting Ethiopian and Russian churchmen...). Overall, he feel that "no longer identifiable oral accounts", mentioned by Fra Mauro himself (p. 33), were an important source in the creation of the map, so, in a sense, many critical "sources" of it probably never existed as written documents; and we probably should agree with him.
At the same time, it seems that quite a few silly statements, or at least unexpected omissions, are hidden in plain view among the books' annotations. For example, the famous seven 15th-century Chinese expeditions to the Indian Ocean are described as being "ordered by emperor Zheng Ho" (item 19, pp. 178-179). (Hint 1: the emperors at the time were Yongle and Xuande; Zheng He was the eunuch in charge of the fleet. Hint 2: with Chinese names, you either use the modern Pinyin transcription [e.g. Zheng He] or the more traditional Wade-Giles [Cheng Ho], but try not to mix the two, at least not in the same name). Mozhaisk (the center of a small Russian principality west of Moscow) is described as having become "famous for its resistance of the Mongols in 1237-40" (pp. 91-92). (Hint: the small city famous for its resistance to the Mongols during that invasion was Kozelsk; I don't believe there was anything ever said about Mozhaisk in that regard). While "Provincia Mordua" is absolutely correctly linked to the Mordvin (Mordva) people, it is quite amusing to read that the nearby "Provincia Quier" "suggests a reference to the city of Kirov" (p. 93). (Hint: Kirov was so named after the pseudonym of a Soviet Communist leader, S.M. Kirov, in the 1930s; the place was known as Vyatka or Khlynov during the preceding 1000 years.)
Neither of these issues is a major one, and one cannot expect them all to be visible to any single author or editor; but if they are noticeable even to a casual reader, I wonder what an expert in the historical geography of a particular region would say if asked to proofread the chapter on the area of his expertise. The book probably could have benefited from having such a proofreading done in advance of its publication. Nonetheless, even as it is, this weighty volume is a valuable addition for any research library with a budget to afford it and the shelf space to go with it.