Background is as follows:
A coworker has been invited to publish her dissertation, however central to the work are some maps that were gathered from an archive holding the primary sources.
The applicable copyright law is 70 years after the authors death, 70 years after creation of the map if the author is unknown, all of the used works are well outside this timeframe and therefore should be within the public domain.
The archive however demands royalties for gathered works in the event of a formal publication.
Can this be safely ignored since they are not in any way copyright holders or are there complications.
I Imagine that this problem has occurred to some professionals here so i formally ask for some clarification or advice.
Thanks in advance.
You can find information about copyright law at Copyright.gov Modern copyright law is fairly uniform around the world thanks to the Berne Convention, but that was not true 200 years ago. Copyright law has changed many times in the last 200 years and it is unlikely that the applicable copyright law for a 200 year old work is 70 years after the authors death or 70 years after the creation of the map if the author is unknown. It would take more facts to know what the correct law is, but I am confident that it is not that. Odds are very high that the work is in the public domain.
Generally, if a work is published prior to 1923 you can be fairly comfortable that it is in the public domain; however, law often is a matter of shades of grey rather than black and white, so there may be exceptions. Of course, works published after 1923 also can be in the public domain, however, whether they are takes greater inquiry.
Just because the work is in the public domain does not mean that there may not be other laws applicable. It may be possible for an archive of public domain works to license access to those works, and in that case, the archive's ability to collect royalties might be based on a contract rather than a copyright. The royalties, in that case, may be for an access license rather than for copyright license, which changes the remedies, but does not eliminate them.
My suggestion would be for your colleague to contact the archive to find out what agreement she or he signed with them. Then have your coworker take it to an attorney to decide whether to pay the royalty. If the cost of the royalty is less than the cost of a legal opinion, they might consider just paying it.
Another alternative is to locate the maps from a different, non-royalty-demanding source.
Personally, I think it would be risky for a professional to ignore a possible license such as this. If nothing else, it could result in damage to the professional's reputation akin to plagiarism and could result in significant financial loss.
I have encountered a similar issue with regards to out-of-copyright texts made available through an online archive. Note that I am in no way a copyright lawyer, nor am I giving you any legal advice.
Anything that is out-of-copyright and in the public domain is indeed out-of-copyright. Mere reproduction of that material, i.e. digitising it and making it available, does not itself create any new rights over the material. There is no creativity component there, no new right is brought into being. So if the archive is claiming copyright, technically that is legal copyright nonsense.
However, the may have terms of use, which seems to be what you are saying. That is trickier. In my view they have no legal basis for asserting a claim to royalties or any payment, except that presumably you have entered into a dubious contract just by using their archive.
Part of the issue is how much legal liability your coworker is willing to risk. I suspect not very much if they are at a career stage of publishing their dissertation. In that case, consider re-sourcing the maps. Try and find an alternate holding, that does not have the restrictive licence, and use that as the basis for the publication. Explicitly cite it as where the images were drawn from.
I think some of these 'licenses' especially when they falsely make 'copyright' claims could be contested, but I suspect most of us are simply not in a position to risk that.