Before using a chainsaw, it is best to understand all of its parts, built in safety features, maintenance requirements, and the forces in play once you rev its small but powerful engine. If you own a saw, bring it to this Arnold Arboretum class, to be held Saturday, July 26, from 9 – 12:30 in the Hunnewell Building Equipment Garage (and you know you’ve always wanted to see the Equipment Garage – this of what must be stored there!) If you don’t own a saw but intend to purchase one, wait until you’ve attended the class to learn which styles and features are best for your size and needs. Participants should bring safety goggles, gloves, and ear protection. Dress for the outdoors and bring a snack and beverage. Head arborist John DelRosso will conduct the session. A class on use and felling techniques will be offered on October 4. Registrants must sign an Assumption of Risk and Release to participate. Fee $45 Arboretum member, $58 nonmember. Register on line at https://my.arboretum.harvard.edu/Policies.aspx.