Abstract: Cooling jets 1 are provided with a longitudinal aspect 2 greater than width 3. Thus, the coolant flow through the jet 1 is less susceptible to deflection by lateral or cross flows presented to that coolant flow such that cooling by impingement of the coolant flow upon a surface 7 to be cooled is improved. Typically, a plurality of jets 1 are provided in a housing wall 8. These jets 1 will be arranged in an appropriate pattern to achieve cooling by flow impingement upon the surface 7 to be cooled. Possibly, a plurality of jets 1 in an appropriate pattern may be arranged upstream of conventional circular coolant jets in order to provide some protection for those circular coolant jets from lateral or cross flow.