This demonstration is to show you how to find and indicate by coordinates where you might find a given dot or other sample on a microscope slide. In various orders-- it doesn't matter if it's done in a number of different orders-- place the slide carefully on the stage. Switching on at the mains. Switching on at the microscope. You have an adjustable light intensity here, the rheostat. It's a good idea to have it somewhere in the middle, so you don't blind yourself. You start with any of these samples at the lowest magnification, 4-- or, if you wish, times 10. Standing back from the microscope, rack the stage up to its fullest height. And pull the eyepieces down until they're comfortable for you and give you a good binocular view. And then, having got the slide in position, you can use the x/y knobs until you find your sample. In good practice, if you couldn't see the sample, you would use a battlement technique. So in other words, you're going-- if you like-- up, along, down, along, up. And so you covered the slide in a recognized and structured way. I'm going straight to the dot here, because I can actually see it without the microscope. I have it centered. I'm using the coarse focus and the fine focus, until I have it clearly positioned right in the center of my view. I can then use the Vernier scale-- x and y scale-- in order to pinpoint exactly for the next user, where this particular sample might be. If, for example, it was a very small sample, if it was surrounded by debris. So, for example, here-- if you look at the small scale, node 10, against the large scale node 50. First of all, to get your gross reading, you will see where the zero matches against the largest scale. And in this particular situation, it's just between the 18 and 19, and then you would need to have fine adjustment to give you the decimal point. And the decimal point will be where the lines here line up exactly. And in this case, it looks like it's around about 4 on this small scale. So the final reading will be 18.4. And the same would go for the scale at the back as well. When you've finished, you can remove your slide. You may want to look at another slide. If not, switch off. Move the eyepieces back, rack the stage down for the next person. If you've used a greater magnification, or if you're somewhere in position there, move it back down for the next person to the lowest magnification. Switch off at the wall, finally.