It was still a sunny day, and it was less than half an hour before the lead-colored clouds pushed in from the southeast, thick as a winter quilt.

[This weather, it's scary, is it going to snow? ] 】

[Like, I remember the professor said yesterday that it would snow the day after tomorrow, but it's only the next day?] 】

[There are errors in weather forecasts, right? 】

[Fang Shen hurry up and run, otherwise it's too late! ] 】

The sailors were anxious when they saw this cloud, they still vividly remembered the power of the last blizzard, if they were trapped, the glider could not say whether it could fly, and the geese and birds could be frozen to death.

Etienne nervously tugged at Bi Fang's robe.

"Boss, it's going to snow."

Bi Fang naturally saw the clouds slowly drifting over, but he was not in a hurry, it was useless to be anxious, the more anxious he was, the more he couldn't figure it out.

"Don't worry, it's useless to be anxious, there is still some time for the clouds to drift over, the most important thing for us is to find the current position, determine the direction and then fly, otherwise the route may be more and more deviated, in case of running into the human city, the geese and birds will remember it in the future, it is very dangerous."

"You can go and put out the fire first, first pick a few pieces of charcoal and wrap them in soil and take them away, then pour them with water, remember to cover them with soil."

Hearing Bi Fang say this, Etienne could only endure it temporarily, according to Bi Fang's actions, but his constantly shaking feet still exposed his nervousness.

Bi Fang explained to the audience while calculating, as if he was not panicking at all, but a discerning person could still see that he was recalculating a value.

This value was miscalculated.

"The number of solar elevation angles = ar (stick height/shadow length), and then calculate the latitude of the observation point = 90 - the number of solar elevation angles + the number of solar declination degrees obtained from the calendar, and the latitude is calculated in this way."

"If the days are sunny in the future, the accuracy can be improved by repeatedly observing and calculating the average several times. If this method is calculated properly, the measurement accuracy error will be less than 1/3000, and the positioning accuracy can not exceed 4 kilometers. ”

Bi Fang's hands were significantly quickened, and his words became tighter and tighter, and the numbers were even more connected together.

"There are two most accurate days of the year to measure the position of the sun: the spring equinox and the autumnal equinox, because these two days are the same length as the day and night in the world, the true solar time and the peaceful solar time are the same, and it is also necessary to understand the meridian in the eastern eight region, which is 120 degrees east longitude."

"This longitude happens to pass through Hangzhou instead of the capital, and the so-called capital time is actually the actual local time in Hangzhou, and the time difference in calculating the longitude is to be summarized as the difference in the geographical distance from Hangzhou."

The more Etienne looked, the more anxious he became, as if he was about to jump to his feet, constantly urging on the side, and even went to untie the glider's body tied to the tree.

"Are you alright?"

"It's coming."

"Are you alright?"

"It's coming, it's coming, it's coming! You go collect the clothes! ”

Bi Fang's brows furrowed, he knew better than anyone else that the clouds seemed to be moving slowly, but in fact they were rushing at a speed of more than forty or even fifty kilometers per hour, almost the same speed as a car!

It only takes less than ten minutes to catch up with them!

"Are you alright?" Etienne clutched her jacket and jumped to her feet as she watched the clouds that were almost falling overhead.

This time Bi Fang didn't speak, he opened the manuscript paper, the pencil stroked, and a coordinate jumped on the paper.

(69°1'N, 24°76'E)!

[, awesome! Really work it out! 】

[It's awesome! 】

【Spaceship and knee send!】 】

[The big guy who does math problems at the moment of life and death! ] Who else! 】

[What? A blizzard is coming? Please let me finish this question first]

"Let's go, get on the plane!"

Etienne nodded excitedly, quickly recalled the goose bird, jumped on the glider, and Bi Fang followed behind and pulled out the map, and found their current location according to the latitude and longitude, and sure enough, it was off!

The route that was originally in the southwest direction has been changed to the southeast direction!

Bi Fang put on some damp clothes, put away the map and came to the lake, saw Etienne sitting in the driver's seat stunned, and waved him to sit back: "What are you doing?" Sit back! ”

[Hahaha, what teenager doesn't have a heart that wants to drive a glider]

[Fang Shen is scared]

[This is a habit]

Etienne also realized that she was in the wrong position, smiled and climbed to the back row.

Bi Fang sat in the driver's seat, pulled the engine, and the spiral blades rotated rapidly, driving the glider to slide slowly.

Etienne in the back row kept honking the whistle, and some panicked geese and birds gradually gathered and quickly arranged in a herringbone shape.

Fragments of snowflakes began to fall on the surface of the lake for a long time, and Etienne reached out to take them, and found that the snowflakes were surprisingly large, almost the size of beans.

"The snow fell too late and a lot of water vapor built up and could cause a severe sudden snowfall." Bi Fang's expression was serious, and he wished that the propeller would turn faster.

Just far away, everyone didn't feel anything, but now that the clouds were approaching, they found that the clouds were terrifyingly thick, and the sun was almost completely obscured, and there was no daylight to be seen.

The terrible sound of the wind resounded through the sky and disappeared into the vast snow, like a wild soul that had been released.

"If I'm not mistaken, this is Nimbostratus, which is often evenly spread throughout the day, and the thickness is generally 4~5 kilometers, which is equivalent to the height of 10 magic city global financial centers stacked together, which is enough to cover the light of the sun and the moon!"

The sailors who had no concept of data panicked when they heard it.

Finally, as the snow grew heavier and the clouds almost covered the overhead, the glider finally left the water.

The sailors began to cheer, but as soon as the glider took off, a strong wind suddenly lifted the plane, almost 70 degrees upward, scaring the audience almost had a heart attack, but fortunately, Bi Fang pulled the control stick in advance and depressed the nose of the plane, so that he could barely control the plane and take advantage of the wind to climb!

Facing the strong wind, the glider flew extremely fast, and Etienne, who was sitting in the back, felt like he was riding a roller coaster, with a strong sense of back, and it didn't take long for him to start flying away from the clouds and heading out.

As the plane calmed down, Etienne looked behind him and was relieved to see that none of the eighteen geese were missing, all of them safe and sound.

He had just flown so fast, and he was worried that the geese would fall behind.

Bi Fang looked back and saw Etienne's nervousness, and explained: "Don't worry, the wild geese fly very fast, they can fly 68~90 kilometers per hour, even if it is a long journey of more than 5,000 kilometers, it only takes more than a month, which is faster than the wind speed in a blizzard, and the wind direction is downwind, we fly fast, they will not be slow." ”

[It's too dangerous just now, it's good to fly early, otherwise there will be none]

[That's right, if the blizzard comes suddenly, isn't it? ] Fortunately, the plane flies fast]

[Anyway, the last time Lao Fang Mohe didn't measure the latitude and longitude? ] Isn't it possible to point out the rescue? 】

[You are stupid, the essence of measuring latitude and longitude is actually to look at the height of celestial bodies, Mohe was in a snowstorm for a few days, and there was no sunlight, do you look at Nima's celestial bodies? Talking over the brain. 】

[Awesome, there is a grumpy brother who understands! ] It's too strong]

Bi Fang looked at the sailors blowing water and smiled, this time he was indeed lucky to escape before the snowstorm came, but what made him a little worried was that the climate change in Finland would not affect the air flow in the North Sea?

A storm at sea can be much more dangerous than a blizzard on the road.

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