Canadian Gisborne pattern by Bullers
This example, made by Bullers Ltd London, for use in Canada dates from about the 1900s, or so I am led to believe.
However as with several other insulators I have, it is stamped internally, in this case 32. Could this be its year of manufacture or simply a mark made by the worker for internal company accounting?
American Insulator collectors have given this an identity number, U-1135. It measures 2.7/8 inches diameter and 3.7/8 inches in height with an internal thread much larger than standard UK sizes and probably used in conjunction with either a wooden spindle or metal spindle with adaptor.
This image is a computer enhanced portion of the side body and illustrates the complete Bullers mark
There is reputed to be 5 different embossing combinations, one of which is Gisborne's Patent
I have managed to find this image on the web which shows some of the Gisborne embossing variants including variations in physical shape denoted by the U number.
My example U-1135 example does not appear in this montage, maybe because it is not impressed Gisborne Pattern