date of this photo and anything on the purpose of the gathering

[arthurk]

The OP says that it's in the original print. If so, it must have been stuck on the neg (what size was the neg/plate)  or is a genuine object or the original wasn't the original.

See my post from a few days ago:

The image in my browser window (shrink to fit, and excluding the white margins) is about 227mm x 157mm. This is almost exactly the same proportion as a roll film negative image of 3.25" x 2.25" (approx 1.44:1); according to Wikipedia, this format was introduced in 1897. Other negative and plate sizes have different proportions - see https://en.wikipedia.org/wiki/Film_format#Still_photography_film_formats

So, if the white 'sign' was not just a printing error, but an unexposed part of the paper caused by a piece of paper stuck on the negative, I calculate that the paper would have been about 0.84" x 0.27". And the two darker spots on the right of it - could they be holes made by a staple, or stitching? They seem to be about 0.31" apart.

If I'm right about the original being on roll film rather than more expensive glass plate, then it occurs to me that Ray might be partially correct:

A photographer turns up and takes a photo of some sort of gathering hoping to sell umpteen copies to the participants. Every potential purchaser needs to see the photo but the photographer doesn’t want to loose a sale so marks the “sample” photo by placing a piece of tape or card on the negative or simply over part of the image on his enlarging easel to make the image unacceptable for display but not obscuring any important detail so everyone can see themselves.

The result - a large white obtrusive mark on the print!

With roll film it would be a fairly simple matter to take more than one shot, so could the photographer have taken two or more, planning to use the best one for copies to sell? One of the less good ones could be passed around to solicit orders, and if it had a label on it there would be much less chance of someone taking it as a good one without paying.

[Ray T]

The OP says that it's in the original print. If so, it must have been stuck on the neg (what size was the neg/plate)  or is a genuine object or the original wasn't the original.

Anything more or less opaque coming between the printers illumination source and the paper they were printing on would produce this result in exactly the same way as muck on your negative will end up as white spots on your print.

Ray

Please read what I said. Stuck on = place on by whatever means.(add - on neg or printing paper)

I know about printing techniques. I studied photography to postgrad level and taught 'creative photograhy ' on degree courses.

Add - if it wasn't close to or on the neg, the edges would not be so distinct. Also, it could be that that area was masked from the developer solution while processing.

I’ve no idea what I’ve said that’s wrong. Perhaps I should read “Man and Superman”?

[Mhillbilly]

thanks for all the help
lesson learnt that access to the original photo will maximise chance to get a result
learnt that others looking always gives a different perspective
learnt that speculation helps but can also send you down blind alleys

what I can say
probably a club or society gathering, highly likely in London
roughly circa 1900-1909, although likely in the earlier part of that range