Continuity mistake: In the scene where the Baudelaires and Aunt Josephine are looking in the photo album, Violet turns a page. You can see the photo Aunt Josephine does not want the orphans to see, but when Violet turns to the next page, the same photo is there. (00:49:10)
Continuity mistake: In the scene where Count Olaf starts walking from the balcony to the stairs, you can see his right hand when he is saying "lovely home" with no writing. Later when he looks at his hand to remember Violet's name, his hand has writing on it. (00:09:20)
Continuity mistake: When Violet writes the letter B, when she is signing the marriage certificate, the side of the B goes down with a little loop. A few shots later, in a closeup of the signature, the B is different. (01:25:00)
Continuity mistake: When the Baudelaire children set the table for Count Olaf and his acting troupe you can see and hear them set seven places, but when you are shown the aerial view of the table there are only six place settings. (00:18:00)
Continuity mistake: When Mr. Poe is first taking the orphans to Count Olaf's house, the shot from the front seat shows the children in the back seat and Sunny is wiggling around with her right hand by her face. But when the angle changes she is calmer and is leaning her head on her left hand. (00:06:50)
Continuity mistake: When the train is passing the car we get a shot from behind the car and we can see the car is wiggling. When it cuts the car has suddenly stopped to wiggle. (00:27:00)
Continuity mistake: When the orphans are making pasta for Olaf, Klaus takes off a window screen and calls it a strainer. As the camera changes shots the arrangement of water droplets change on the screen. (00:16:35)
Continuity mistake: Before the play when Klaus pulls the "Inheritance Law and You" book out of the camel head prop he has his left arm all the way inside the camel head. When it cuts the Camel head is gone from his arm. (01:12:15)
Continuity mistake: When Violet opens the closet with the rat, she is holding a pile of plates. If you look at the upper plate you can see it has curvy edges. When it cuts from a view inside the closet you can see it is a different plate on top of the pile, because the edges on it are plain. (00:14:20)
Continuity mistake: When the Baudelaires jump over from the broken piece of the house over to the rest of the house, as they land, you can see to the right that there is a big hole in the wall where there should be a window with sprinkles. As they run out of the house, right before it falls in to the lake you can see the sprinkles are suddenly mended. (01:02:05)
Continuity mistake: When Olaf and his acting troupe are gathered and he sits down and says "Now who shall play the most handsome count in the world?", he has his hands folded resting them on his left armrest. When it cuts both hands rests on each armrest. (00:15:45)
Continuity mistake: When the Baudelaire tell Olaf that dinner is served you see two plates on the left side but then the camera angle changes to the Baudelaire's view and now there are three plates. (00:18:10)
Continuity mistake: After the death of Uncle Monty, Stephano says "I do feel somewhat responsible for this tragedy". At the same time you can see a policeman carrying a box passing Violet in the background. When it cuts he passes her again. (00:42:40)
Continuity mistake: When Mr. Poe and the Baudelaires arrive at Uncle Monty's he has his snake twirled around his arm as he reach out to shake Violet's hand. When it cuts the way the snake is twirled around his arm has changed. (00:29:00)
Continuity mistake: When Stephano first arrives it is fairly dark outside. But when Stephano runs back into the Reptile Room and says he really looked forward to the milking it is fairly light through the window. (00:38:30)
Continuity mistake: When we see Sunny biting on the table we can see her shoulder pads close over the edge on the table. When it cuts to we seeing her hanging on to the table with her teeth her shoulder pads are at least five centimeters below the edge of the table. (00:03:35)
Continuity mistake: When Hurricane Herman has started to destroy Aunt Josephine's house, the stove's gas pipe disconnects, then we see the rotary wall telephone partly fall from the wall. The handset falls completely off, but in a subsequent shot when the stove is ablaze, the handset is hanging sideways from the phone's cradle. (00:59:45)
Continuity mistake: When Violet is in the kitchen scrubbing the dishes, if you look right in front of her there is a small rack containing a red box. The end of the red box is over the edge of the rack. When it cuts to Klaus scrubbing, the red box is inside the rack. (00:14:15)
Continuity mistake: When the two ladies are done singing before the play the carpet on the stage is open wide. When it cuts to a close-up of Klaus looking around you can see in the background that the carpet is closed. (01:16:30)
Continuity mistake: When Violet and Klaus are setting the table, Violet puts her first plate on the table. When it cuts she puts it on the table again. (00:17:15)
Answer: A magnifying glass concentrates all the light that goes through it at its focal point, and it is this focal point that needs to be placed on the object which one wants to set on fire. The distance of the focal point to the lens depends on the magnifying glass characteristics, and it is more than likely that Count Olaf chose a glass where the focal point would be situated exactly "37 blocks" away from his house, that is, at the Baudelaire's mansion. When trying to set on fire an object much, much closer, the glass would concentrate much, much less energy, and would only be able to set on fire easily burnt objects, such as thin paper.
AnthonyA