546. Reading by an Oil Lamp

In an introductory note to this chapter, the Kitzur Shulchan Aruch writes that most Jews are already familiar with the prohibited labors of Shabbos and that he is only addressing common situations with which people may not be familiar. Clearly, the laws of Shabbos constitute an area requiring much greater study than this email alone will allow. 80:1 It is forbidden to perform any activity that requires careful attention by the light of an oil lamp. This was prohibited by the Sages so that one should not absentmindedly tilt the lamp in order to improve the light, which would violate the labor of mavir (kindling). Two may read from the same text because if one reaches out to adjust the lamp, the other will stop him. The practice is to be lenient with modern candles (since tilting them has no effect on improving their light - Mishnah Brurah 275:4). However, one needs to make some sort of sign to remind him not to trim off the charred ends of the wicks, which the Rambam considers to be prohibited at the Biblical level. One may not even have a non-Jew trim off the ends of the wicks.

80:2 One may not open a door or a window directly opposite a nearby burning candle because incoming wind may extinguish the flame. (One may be lenient in a case of need and open the door slowly so long as there is no wind outside - Mishnah Brurah 277:3.) One is permitted, however, to close a door or a window. One may neither open nor close the door of a burning oven because this causes the fire to go up and down.