Here is a reply from a costume expert friend who makes period clothes for a living re the date of the silk breeches and useful information about sewing machines! The breeches are also associated with Thomas Graham, Lord Lynedoch through documentary evidence.

"Dear Hugh,

Thank you for the photos of the buttons, they are, in my opinion, contemporary with the 18th C date. Bone was very much used for buttons in the 18th C and probably continued to be used into the 20th C when cheap plastic production took over. Mother of pearl came into common use in the 19th C, though I'm not sure when it started to be used for buttons. Quite often wood, horn, bone and even cardboard was used for the mould for buttons in the 18th C so varying shapes and thicknesses is unsurprising. I don't think the chap in the kilt forum knows very much about 18th C breeches! The drop front, the angle of the seat seam, the height of the back, the adjustability in the centre back, the narrowness of the leg all point to mid to late 18th C. Breeches were worn into the 20th C but not in this shape and would not have been entirely hand sewn. Machine stitching is a very good indicator of date.

Here are some key dates for the sewing machine which may help you dating other items.
1790, Thomas Saint patented a machine to sew canvas & leather it was a single thread chain stitch machine that mainly sewed boots.
1830, Bartholemy Thimonnier (French) invented a machin with a hook tipped needle. By 1841 there were 80 machines sewing French army uniforms
1834, Walter Hunt patented a machine
1846, Elias Howe patented the lockstitch (two thread) machine
1850, Issac M Singer patented the rigid arm & treddle
1850, Allen Benjamin Wilson patented the rotary bobbin (before then there was the shuttle)
1881, Joseph Merrow invented the overlocker and patented it in 1886, the term 'merrowing' was used in the industry.

Prior to the mid 19th C almost everything was entirely hand sewn, by the end of the 19th C almost all the main seams of garments were being machine sewn. The early chain stitch machines continued to be used right into the 20th century. Everything about your silk breeches appears to be contemporary with the 18th C. the only thing that seems odd is the 'velcro'. I've not done any research on the product or its forerunners though from your photograph it looks very like velcro, I suspect that it is a modern addition, though looking closer it looks a bit like a strip of fur. Fur if trimmed very short and attached with the pile facing upward would probably help keep the breeches from riding up a little bit but the knee strap would probably do more - is there a buckle for the strap? The attached file is a scan from a book I have containing line drawings of the main pieces in the cut of mens clothes. This seems to be very close to the breeches you have.

Oh and if your kilt man finds some breeches like this for $100 I'll fight you for them ;-) "

p.s. from Hugh: I have added some more photos of the buttons and other closeups for those interested. The antique "velcro" isn't actually velcro at all but some kind of natural organic fur like material woven onto a linen backing and with a natural grip like velcro!

http://picasaweb.google.com/hughranc...eat=directlink