Scans

The catalogues of the selected libraries inspected by Richard Pflederer include good quality colour illustrations of each separate chart and a representative sheet from each atlas. In most cases the place-names can be read. The libraries in question are Chicago (Newberry Library), Florence (Archivo di Stato), Greenwich (National Maritime Museum), Oxford (Bodleian Library), San Marino (Huntington Library - on which see below). However, this does not apply to the British Library.

Archivio di Stato, Firenze
In 2016, the Florence Archives placed online the 22 charts (with a few maps) in their C.N. (= Carte Nautiche) series. These are of very high quality, can be enlarged to fill the screen, and can be rotated. Given the importance of that collection, which includes the earliest dated chart (Vesconte 1311), the best image of the destroyed Carignano map/chart, signed works by Benincasa, Bertran, Soler and Vallseca, as well as anonymous charts and a few from the later centuries, this is a most welcome addition.

Beinecke Library, Yale University (Beinecke Digital Collections)
This features a 1559 Agnese atlas and charts by Aguiar, F. Beccari, Doran, [Maggiolo], J. Oliva, J. Olives, ben Zara, and an unsigned 15th century work, attributed by Ramon Pujades to Roselli. The scans are excellent and can be rotated [press 'r' for clockwise and Shift 'r' for counter-clockwise]. They can also be downloaded and printed out.
      For bibliographical details see the 2009 Pflederer catalogue (listed above) pp.184-5.

Bibliothèque nationale de France
[Note added 15 January 2018] The easiest way to access the description and image is to use the call number, if you have it. Go to the main Catalogue and search, e.g. "portulans Ge AA 562". It may not be the first entry shown. Clicking on that takes you to the 'Notice bibliographique'. That contains a thumbnail but if you want the high resolution image look to the right 'LOCALISER CE DOCUMENT' and click the red button 'Consulter en ligne'.

No doubt it is also possible to search for a known chartmaker by name.

The BnF collection of portolan charts is much the best in the world. They are engaged in a marvellous project, 'Cartes et atlas-portulans conservés dans les collections publiques françaises', to catalogue and scan all the charts in French public collections. To find a list of the charts or facsimiles that have already been described and/or reproduced, you must, I think, follow one or other of these two routes. It is not clear to me if the information in each is the same, though the first method (announced in June 2012) is much quicker. At that time, there were 497 results via the first route and 559 by the second. However, not all those from the second route have available scans (at least for now):

1. Simply click here {link no longer working} and then select from the sorting options ('pertinence'), such as author, title, date (in either direction). You can also select by the date the scan was placed on the website ('Date mise en ligne'), with the latest listed first (most having been added in 2007). Click on 'Informations détaillées' for that and other details about the chart in question, including the MS number ('Source'). For the full catalogue description, click on 'Relation'.
      To access the scan, click on 'Accéder au document'. 'Feuilleter' leads to a low resolution image instead. For tips, see 'Viewing the images' below.

2. Search the main Catalogue for 'Recherches spécialisées [left margin] - documents cartographiques'; 'Choisir un type de document cartographique'; scroll down to 'Carte portulan'; finally click 'Rechercher'. This brings up a list of 571 entries [30 August 2013 - the number is still (apparently) being added to, though it does not seem to be possible to identify those added since last you checked (but see (1) above)]. To put them in chronological order, select 'Tri croissant', immediately to the right of the default 'Année' option in the right-hand box.
      This brings up a chronological listing, with the inexact dates at the beginning (on the first two pages). Those entries with the black and red pattern have images attached to the descriptions. Click on the + to the left of that. Once you are in the description ('Notice') you bring up the scan by clicking the mauve 'Visualiser' sign and, to enlarge the image to high resolution, click, repeatedly, on the magnifying glass symbols. [It is good to report (February 2012) that the quality for the separate charts has been significantly improved, so that most of the names are now legible.]
      To find the BnF manuscript number (e.g. GE DD- 687 (RES))- which does not appear where you would expect it at the top of the Notice - look at the lowest box in the right-hand margin.
      When viewing a chart, there is no direct link to the catalogue entry ('Notice'). Instead, click on 'Detailed Information' top right. This leads you to an abbreviated record from which you can pick out the full text via the link next to 'Relation'.
      There is a unique URL for both the Notice and the page of scan(s) for each atlas or chart, but, if you want to return to those, make a note of the details when you are in the page concerned as they are not easy to find.

Unfortunately the brief entries in the general index are very inadequate and do not show the unique BnF manuscript number. Nor is it always clear if the chart is actually dated or has been given an estimated year. A majority of the charts are not clearly dated but those that are can be found in the Microsoft Word Table listing of Post-1469 charts. Each has a link leading to its image page(s).

Viewing the images
To read the names, which face in all directions, it is necessary to rotate the chart. However, when you do that there is a mismatch between what is shown on the left-hand navigation screen and what appears on the main screen. It seems that the enlarged section on the left screen relates to the image before it was rotated. The best way to proceed seems to be to enlarge to the full extent, place the area you are interested in at the middle of the screen, and then rotate. Afterwards, rotate back to the original orientation and move to a new area.

For bibliographical details see the 2009 Pflederer catalogue (listed above) pp.41-83.

In, it seems, mid-2015, the following page was added to the BnF site: 'Cartes marines sur parchemin'. This offers alternative access routes to the collection of portolan and other charts, e.g. Les plus beaux portulans, Accès par grands espaces maritimes, Accès par lieux de production, or Albums.

British Library
The British Library has made available a selection of their portolan charts, including, most notably, the 37-sheet Cornaro Atlas, via the Pelagios Project . See also Wikimedia Commons, Category: Portolan charts.

The online Catalogue of Illuminated Manuscripts includes just one of the BL's items, namely the late Sanudo/Vesconte atlas: Add.MS. 27376*.

Huntington Library, San Marino
Links are provided to the individual charts in their HM order, but you can consult the Huntington Catalogue: Guide To Medieval and Renaissance Manuscripts in the Huntington Library. See also Chart of the portolan atlases: geographical areas on maps and portolan atlases. This provides access to about 35 portolan atlases and charts. They are the best scans I have found and they can be enlarged and printed off in sections or downloaded. Unfortunately they cannot be rotated on the screen.

MEDEA-Chart Database
This is the only source for images, from any period, preserved anywhere. A growing catalogue of charts and atlases, through time, combining thousands of bibliographical entries, allowing a wide range of searching techniques, as well as providing digital images (many enlargeable to legible resolution). The database is one aspect of MEDEA- CHART: The Medieval and Early Modern Nautical Charts.

National Maritime Museum, Greenwich
The website of the National Maritime Museum, Greenwich, London has a large number of images of portolan charts. Unfortunately, following alterations to the website (noted in January 2012), it is no longer possible to access a browsing list of those, nor can the images any longer be enlarged so that the place-names are legible. Whatever the reason for this change, it renders that formerly significant collection of images useless for serious research purposes.
      If you are interested in a medium resolution 'recognition' view of a chart, you should still be able to find it, but with some difficulty, given the removal of the previous special Collections category devoted to portolan charts. The best advice is to use the Search box on the homepage and enter 'vellum'. This brings up over 400 items. Refining by century will remove images such as telescopes. What is left will be the portolan charts, individual sheets from portolan atlases, and some other material.
      If you are looking for a chart whose author you know, enter his name. It seems to be possible to search for a known call-number - e.g. for the Domenech chart, G230:1/9 - but you need to omit the slash and whatever follows that, and then pick from the selection you are given. Once you have found the image, this has a unique URL for future use, as for example here.
      Protests have been made via the NMM's < http://blogs.rmg.co.uk/collections/2012/01/03/the_revamped_collections_websi/#comment-103 > >Blog (January 2012) and it is hoped that the original, high resolution versions of the chart scans may be reinstated. For that reason, the old links have been left in, e.g., from the Later Charts Table (a Microsoft Word document), even though they currently take you to a relatively low resolution image, with the names illegible.
      For bibliographical details see the 2009 Pflederer catalogue (listed above) pp.10-16.

Portuguese charts
All of these will be reproduced in Portugaliae Monumenta Cartographica, but are not listed here. Alternatively, use the medium resolution scans from the Portuguese Archives

Vatican Library
All their charts and atlases, pre-1501, [with the sole exception of Pal.lat.1362A) are included in the DigiVatLib and can be found by searching for 'portolan', which links to the 1986 'Census' of earlier charts. Most are enlargeable to high resolution. Later works were not checked but certainly Borgia.IV , Borgia.VIII and Borgia.XIII are included as well.

Works checked for images

La Roncière, Monique & Michel Mollat du Jourdin. Les Portulans: Cartes marines du XIIIe au XVIIe siècle (Fribourg: Office du Livre, 1984). English edition, trans. L. le R. Dethan, Sea charts of the early explorers: 13th to 17th century (London: Thames & Hudson, 1984).

Lepore, Fortunato, Marco Piccardi & Enzo Pranzini. Costa e arcipelago toscano nel Kitab i Bahriye di Piri Reis. Un confronto cartografico (secoli XIII-XVII). (Pisa: Felici Editore, 2011). With 52 scans of charts (some additional to those in the book) some in high resolution, on a separate CD-ROM, that can be zoomed and rotated (reflecting the book's focus, all the sample sheets from atlases concentrate on Italy and the central Mediterranean).

PMC. Cortesão, Armando & Avelino Teixeira da Mota. Portugaliae monumenta cartographica. 6 vols (Lisbon, 1960). And also the second, reduced-size edition, with an additional Volume VI by Alfredo Pinheiro Marques ([Lisbon]: Imprensa Nacional - Casa da Moeda, 1987).

Ristow, Walter W. & R.A. Skelton. Nautical charts on vellum in the Library of Congress (Library of Congress, 1977).

Rosselló i Verger, Vicenç M. Portolans procedents de col.leccions espanyoles. Segles XV-XVII [catalogue of an exhibition at the Salò Tinell, Barcelona, on the occasion of the 17th conference of the International Cartographic Association, 5-17 September 1995] (including the essay: 'Cartes i atles portolans de les col.leccions espanyoles' (pp.9-60)) [also in English, French and Spanish] (Barcelona: Institut Cartogràfic de Catalunya, 1995).

Sider, Sandra, et al. Maps, charts, globes: five centuries of exploration: a new edition of E.L. Stevenson's "Portolan charts" and catalogue of the 1992 Exhibition (New York: Hispanic Society of America, 1992).

Tolias, George. The Greek portolan charts, 15th-17th centuries: a contribution to the Mediterranean cartography of the modern period (Athens: Olkos, 1999).