I’ve posted the first Scientific American Series which spans the period from 1845 to mid-1859. That comprises Volumes 1-14. They issued one each week so generally 52 issues each year. In mid 1859 they cut volume 14 off at issue 42 and started a totally new series with a new issue every 2 weeks for 26 a year.
There are a few issues missing in some of them such as Volume 6 which I couldn’t find at any of the sources. I’ve added those to my “Missing” list which I periodically check for.
I’m working through the rest of the volumes and will post them in sections as I get groups of them finished. The newer series runs through Volume 99 and there don’t appear to be as many missing from those as from the First Series.
The Scientific Americans are particularly nice since they delve into what was, at the time, new emerging technology and try to explain it in terms that common readers would understand. For those of use looking at books on 1800s technology these are extremely useful since they can help make sense of some of the technology which we are not familiar with yet would like to learn.