Voigtlander Lens

I recently got a circa 1881 Voigtlander lens (based on the s/n list Dead Link Removed). It looks almost identical to this one only is a bit smaller and has a one on it instead of the 3.

It covers 5x7 with no problem but I don't have anything bigger than that to see what its limit is. Both the front and back glass show two bright, larger reflections and a third small dim one.

Can anyone tell me anything more about this lens?

Thanks,
Dan

Quite likely an Aplanat, yes. Also known as Rapid Rectilinear, but they were patented simultaneously by two different people in Germany and UK. So they have two different names (and very slight differences in construction).

The number 1 means, in most cases, that it was intended for use on the smallest format, 9x12cm. Just a little bit smaller than 4x5". So it may illuminate the whole 5x7" ground glass, but I doubt if there is any sharpness to speak of in the corners.