Whenever I see hand lenses, I am reminded of my father using it to read fine prints - moving/focusing it towards and away. And also of my experiments with it in my boyhood days. Then I focused a lens on the house wall to get the inverted image of the windows! I tried also to make a camera with it, and a negative film of the inverted windows' image! With it I even viewed film strips on dark room wall using battery light as light source! I also used it outdoors on a piece of paper or a wisp of cotton to burn them - by sharp focusing of sun rays!
There is a double pump that receives fluid from various places and pumps it to be purified. And at the same time it receives also already purified fluid and pumps it to those various places. This pump is our wonderful Heart pumping the fluid, the blood!
In school days, I found often shells of snails stuck to the stems of bushy plants. I thought they are the shells of dead snails. Then, I tried hardly to remove one of them from the plant's stem till it give in. On inspection of its mouth I found a white paper-like structure closing it. I pierced it with a stick to strip it off. To my surprise there was the snail still alive, retracting itself further into the shell! This snail is the Vineyard Snail (Cernuella virgata or Hellicella virgata , 'Natthai' in Tamil).
