Changes

Mark B. Fry's coolship SA:V calculator will calculate the SA:V for cylindrical kettles(updated by Joe Idoni to include a second tab for rectangular coolships):* [https://docs.google.com/spreadsheets/d/1HFBTCt99OQ9-jSGI9jBZXwC6SqtZZVwlpXYw2rjLO4k/edit#gid=90184859 Coolship SA:V calculator with approximation of cooling rate Original spreadsheet by Mark B. Fry (download and save a copy to use).]* [https://docs.google.com/spreadsheets/d/1gB4347cP70Sw6topMoOvDydMYQcS2PF7M0Yl0vgbZbk/edit#gid=1777054704 Updated version by Joe Idoni with tab for rectangular coolships (second tab; download and save a copy to use).]