![](https://coimages.sciencemuseumgroup.org.uk/132/2/large_thumbnail_2015_0015__0010_.jpg)
Sample perspex window used in researching high pressure windows
![Sample Perspex window used by Ian Gilchrist in researching high](https://coimages.sciencemuseumgroup.org.uk/429/898/small_thumbnail_smg00173279.jpg)
![Sample Perspex window used by Ian Gilchrist in researching high](https://coimages.sciencemuseumgroup.org.uk/3/398/small_thumbnail_2007_0148__0001_.jpg)
![Sample Perspex window used by Ian Gilchrist in researching high](https://coimages.sciencemuseumgroup.org.uk/3/400/small_thumbnail_2007_0149__0002_.jpg)
Sample Perspex window used by Ian Gilchrist in researching high pressure windows for Benthic pressure trap. An unlubricated window pressurised once to 304 MPa. The grooves in the low pressure face had been cut before the window was tested in an attempt to promote window failure. There is a relative absence of surface cracks on the conical surface of the window.