Monday, April 26, 2010

Link redirection and ID stability

We have recently updated BHL to allow us to better handle situations where titles or items are taken offline. The key problem that occurs when things are taken offline is that the links to those items are now broken. Anyone who has linked to those titles/items or uses our data exports and/or APIs to access them is affected.

In some cases, titles/items are taken offline because of serious quality issues with the scans or because of copyright concerns. In those cases, there is little we can do other than "break" the links to those items.

In other cases, however, items may be rescanned and replaced by a new item. Or, two libraries might contribute the same title to BHL, and we at BHL combined those two titles into one. These are the cases for which we can preserve the links.

The change we have made is to allow our librarians to designate a "replaced by" identifier when titles/items are taken offline. So, if item 1000 is rescanned as item 2000, we can now take item 1000 offline, but redirect incoming requests for that item to item 2000. The same is now possible when two (or more) titles are merged into one... requests for the titles that are taken offline as a part of the merging process can now be redirected to the title that remains online.

Following is a more detailed explanation of how the various parts of BHL are affected.

If a title/item has been set to redirect to another title/item, then when you attempt to access the original page you will be automatically redirected to its replacement.

For example, if you navigate to you will be redirected to . Likewise, navigating to will result in a redirect to .

Data Exports

The bulk data exports that are generated on a monthly basis contain only active items and published titles. Because of this, redirects are not indicated in the data exports (since redirects apply to item that are no longer active and/or published).

Keep in mind, though, that if a third party has a copy of an older data export which contains titles/items that have subsequently been replaced, then when that third party follows the links contained in the exports they will be automatically be redirected to the correct title/item.


The following API methods honor the redirects:


Using the earlier examples, a call to GetTitlemMetadata with a parameter of 3935 will return the metadata for title 7347. Likewise, a call to GetItemMetadata with a parameter of 23127 will return the metadata for item 28474.

Detailed information our APIs can be found here:

Final Thoughts

It's possible that you may find some titles/items that have a replacement item but have not been properly redirected. If that is the case, kindly let us know. Also, keep in mind that some titles/items may be taken offline and there may not be a valid replacement available. Please accept our apologies if you are affected by this situation.

Tuesday, April 20, 2010

Book of the Week: Highlighting the Australian Giant Cuttlefish

For this week's book of the week, we highlight another of EOL's featured species - Sepia apama, perhaps better-known as the Australian Giant Cuttlefish. With a maximum recorded mantle length of 520 mm and a weight of 6.2 kg, the Sepia apama is the largest species of cuttlefish in the world.

Australian Giant Cuttlefish are masters of camouflage. They are capable of altering their appearance in dozens of ways in order to mimic their surroundings. For instance, not only can they alter their skin patterns, but they are also capable of changing their skin texture as the need arises. Such ingenious texture alterations are achieved by either arm contortions, which allow the animal to mimic nearby algae, or through the "sprouting" of papillae, or "spiky skin projections," which mimic "the physical texture of the surrounding seaweed, rock or coral."

Take a few minutes to investigate this amazing critter on EOL, and dive a little deeper into the early development of cuttlefish at large (Sepia officinalis, the Common Cuttlefish) in this week's book of the week, Recherches sur les premières phases du développement de la seiche (Sepia officinalis), by Louis Marius Vialleton (1888). The plates located at the end of this book give a particularly detailed view of the development of these intelligent invertebrates.

This week's Book of the Week, Recherches sur les premières phases du développement de la seiche (Sepia officinalis), by Louis Marius Vialleton (1888), was contributed by the Smithsonian Institution.

Thursday, April 15, 2010

Updates to API & Tech Documents

New updates have been released for the BHL API, plus new documentation about data exports and other services are now available on the Developer Tools and API section of the BHL wiki.

The BHL Application Programming Interface (API) is a set of web services that can be invoked via HTTP queries (GET/POST requests) or SOAP. Responses can be received in one of three formats: JSON, XML, or XML wrapped in a SOAP envelope.

Version 1 (formerly the BHL Name Services): Updated documentation for the first version of the API can be found at This version of the API is provided solely to maintain backwards compatibility.

Version 2: The documentation for the latest version of the API can be found at The first version of the API was limited to data related to scientific names found in the BHL collection; version 2 adds access to title, author, volume, and page information. Please note that users are required to obtain an API Key from in order to use version 2 of the API. This is the preferred version of the API.

View the API Privacy Policy and Terms Of Use.

Wednesday, April 14, 2010

Conservation 101: Least Concern

As part of our on-going series related to the International Year of Biodiversity, we'll take a closer look at conservation status and occasionally highlight species in each rank. The International Union for the Conservation of Nature and Natural Resources is the primary global organization responsible for risk assessment organizes threat in 8 categories--Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Conservation Dependent, near Threatened, and Least Concerned.

Pictured above, we have the Oklahoma State bird, the scissor-tailed flycatcher, or Tyrannus forficatus, first described in 1789. They aggressively defend their territories against intrusions by conspecifics and in the spring, a flamboyant performance with their long scissor-like tail, is part of the courtship dance. Such self-assertive behavior has served this bird well; it's squarely situated in the Least Concern ranking for threat of extinction, so generations to come can enjoy this fascinating species.
Enjoy. :)

Monday, April 5, 2010

Book of the Week: A Call to Garden!

Spring is in the air, and that means blooms are just around the corner! And this, of course, means that all you gardeners out there can dig your potting tools out of the shed and get ready to get your hands dirty. We thought we'd help by highlighting one of the many valuable gardening guides in our collection. As we sifted through our collection, one book in particular caught our eye. It seems that gardening isn't just a modern pastime (not that this was ever supposed), but in fact it was a popular activity for women of the nineteenth century. Many guides to "ladies' gardening" were published during that time, highlighting the different ways to stir and measure soil, sow seeds, and prune overzealous growth. Case in point: Gardening for Ladies. This 1851 publication provides all of the instruction a lady of nineteenth century America could ask for in regards to gardening, starting with the basics. Indeed, the work took a decided view of "begin at the beginning," supposing no "previous knowledge of the subject," as their European counterparts, they claimed, were so apt to do. So, before you dig down into the soil, take a look at this week's book of the week, Gardening for Ladies. Even if you aren't a nineteenth century lady (and if you are and still intend to garden, more power to you!), you still might learn something!

This week's book of the week, Gardening for Ladies (1851), by Mrs. Jane Loudon, was contributed by the New York Botanical Garden.

Thursday, April 1, 2010

Groundbreaking News!

BHL is thrilled to announce that construction has already begun on our brand new brick-and-mortar library that will house a physical copy of each of the over 159,000 volumes currently digitized and, until now, only available online. Demand for physical access to the digitized copies has been steadily growing over the years, so in an effort to reach users without access to the Internet, we've begun the painstaking process of transcription. We realize that much of the value of the BHL collection is derived from the sense of history that one receives while researching these texts--many 300 and 400 years old. In order to preserve that sense, we are replicating the publishing processes and techniques that were common during and before the peak of the industrial revolution.

It's not cheap and it's far from easy, but we think you'll understand why we have gone to all the trouble as you enter the lobby of our new building. The card catalog alone sprawls an impressive half acre. Librarians will be on hand to begin issuing BHL library cards for lending as early as next Fall. See You Soon!

BTW, April Fool's! ;-)