Parasol rig: Pilcher of London and Wilson of Dublin demonstrate their 'Cyclone' yacht

[Robert Biegler]

Does anyone know anything about the boat in these pictures? https://www.prints-online.com/parasol-yacht-602267.html
https://www.scienceandsociety.co.uk/res ... e=10311101
https://www.prints-online.com/royal-aer ... 05275.html
Google translates the text that goes with the first link as follows:
The new kind of sails that represent our engraving was successfully tested in the waters of Southampton by the inventors Mr Percy S. Pilcher of London and Mr M. Wilson of Dublin. With the usual sails of our ships, a portion of the force of the wind tends to tilt the boat, and if this force becomes too great relative to the weight of the keel, the boat capsizes. The parasol sail eliminates the danger because the action of wind tends to lift the boat. Indeed, the lifting force is parallel to the mast, the latter being fixed in the axis of the boat without being connected to the sides, it follows that the hull does not undergo any inclination (Fig 1 and 2).
The mat is mounted on a pivot and can move in two right-angle slides (fig 3).
The sail is elliptical in shape, with a long axis in the horizontal, it is arranged on a mount that resembles that of an umbrella and can fold over the direction of the small axis.
The usual inclination of the sail is 45° to the horizon, but this angle can be modified according to the force of the wind.
According to the inventors, this sail is called

That is all I could find. Can anyone point me to more information?

[AlexQ23]

Hi Robert,
Marchaj mention this type of rig on page 126 in"Aero-hydrodynamics of sailing" and it seems that it's in Cowes that this boat was tested. May be there...?

[Robert Biegler]

My university library has it. I ordered the 1979 edition, because the 2000 edition is already out on loan. I'll see what I can find.

What I specifically want to know is whether the sail was at a fixed angle relative to the mast. The photographs don't have high enough resolution to tell me. The drawings suggest that, like an umbrealla, the sail's position relative to the mast was fixed, which means that any adjustment relative to the wind must have been by changing course or swinging the mast. I also think that it could be swung only through 180 degrees, meaning the boat could only tack in light wind, if at all, and more likely wore around.

[Robert Biegler]

I found the entry in Marchaj. The photo has a better resolution than what I found online, but still not quite enough. I also found a letter that Pilcher sent to the journal Nature in 1897 (https://www.nature.com/articles/056342a0). That is a bit more informative. Pilcher first descrobes the idea of a non-heeling rig, then says:
"The sail is made oval, with the major axis horizontal, so as to be able to carry more sail with a definite height of mast.
The training in the horizontal direction is accomplished by means of a turntable, and the elevating and lowering by two tackles.
There is a blaance weight which helps in elevating the mast, and which is sufficient to balance the dead weight of the sail in a calm, not inclining the boat.
The sail can be set and furled in a minute; it does not close like an umbrealla, but each side shuts up like a fan."

If the sail could be trimmed around two or even three axes, Pilcher presumably would have mentioned something so crucial. So I think the only adjustement is around the vertical axis.

The passage in Marchaj mentions a J Rowland describing hiw experience with the rig in Hachts and Yachting of 17th July 1959. I have searched for a way to get hold of a copy of that magazine, so far without success. Does anyone have a suggestion?