Some rules: (1) _Avoid flickering light_--fatigue and nerves result from flickers. (2) _Use shaded lamps._ More diffused light from a large source gives better light than from a small. (3) _Don’t judge the light by the lamp._ The lamp doesn’t give light. The light which comes directly from the lamp to the eye does no good and may interfere with the useful light which has gone from the lamp to the surrounding objects and thence to the eye. (4) _Do not face the light._ It is well to have the light from above over the left shoulder. This plan obviates the shining surfaces of paper, table tops etc. from interfering with pleasant seeing. In this way too, you do not see the lamp itself. If you have to shade your book the light is wrong for _you_. (5) _Avoid brilliant reflection_ of the lamp. (No matter how brilliant your own reflection may be!) Glossy paper in books especially for children should be “verboten.” (6) _Keep lamp away from your work_, your eye likes not to concentrate on concentrated light. The desk light or factory light lying “away” rather than “next to” is far better for worker. A special reading lamp is good but is often pleasanter when used in connection with a soft general lighting. (7) _Vertical light carrying fixtures_ are best--old ones can be bent to carry light vertically. CHAPTER XXXVII TIN WARE, RUBBER AND PAPER Tin is one of the oldest metals in the world. The Ancient Greeks and the Ancient Hebrews made mention of it frequently. Before the advent of the Kingly Aluminum and the Queenly Enamels, agates, granites etc., tin was used extensively in the kitchen, but now the cooking utensil is very rarely tin and rightly so. However, tin still remains a good thing for various things in the home and is well worth employing in different ways. These ways will interest you to consider. However--firstly--all things made of tin to-day are but steel or iron dip and coated with tin. Tin melts at a comparatively low temperature and is besides affected by acids. That is why baking, stewing, etc. are not to be done with tin utensils plus acid food. The dark rings on baked apples cooked in a tin dish show very plainly what acid and tin do in combination. In buying tin the criterion is its weight. It is only wise to buy tin ware in the best shops, because small, but out of the way hardware shops can rarely afford to keep on hand the best tinware. It should, of course, adhere closely to the lines of all other utensils in that it must be smoothe without rough globules, without seams, which might catch food or dust particles to create an aftermath condition difficult to rectify. CLEANING