 So today we want to talk about parts of the microscope. There are all sorts of different compound microscopes. They come in different shapes and configurations, but this particular compound microscope is said to be a biocular microscope because it has two oculars, one for each eye. Some microscopes are monocular microscopes and they would just have one ocular, one eyepiece. This part of the microscope is said to be the body tube and in today's microscopes they aren't very tube shape but we still use that terminology. This part of the microscope is called the arm and it's a convenient handle to carry the microscope by. This part of the microscope is called the revolving nosepiece or the turrent and you can see that it said to be the revolving nosepiece because the various objectives revolve around the nosepiece. This microscope has three objectives. Some microscopes have four. There's a space here for a fourth one but this microscope doesn't have one screwed in there. This part of the microscope is referred to as the stage and I think it's called the stage because that's where the performance happens so to speak. This is where we put our microscope slide and you can see there are stage clips that hold the microscope slide in place. In order for the microscope to work properly the slide has to be slid all the way back into the cradle created by the stage clips. If I turn the microscope around you can see what we call the mechanical stage knobs and the mechanical stage knobs are what manipulate the stage and more importantly the slide so we can make adjustments to which part of the specimen we would like to look at. Now in the arm we find the adjustment knobs and there are two adjustment knobs. The larger adjustment knob is the course adjustment knob and you can see as I rotate the course adjustment knob it makes very gross changes to the working distance which is the distance between the specimen and the objective. So that's the course adjustment knob. Then we have the fine adjustment knob and as we rotate the fine adjustment knob it just makes very fine changes to the working distance. Now below the microscope and I'm going to turn this up on the side just so you can see it is what we refer to as the condenser and there is an adjustment knob that we can slide back and forth and that manipulates the amount of light coming through the specimen. So if we can zoom in right here as I move that adjustment knob back and forth you can see how the amount of light that moves through the specimen changes. This is an important feature because it allows us to adjust the brightness of our field of view. So you can see in the base of the microscope we have the light source and the light source of course is what illuminates the specimen.