Last year, when Li Ke was preparing to make a pendulum clock, he took out relevant books and taught them to Li Fu, but although Li Ke had drawings here, he did not give the drawings directly.

At first, he told Li Fu about the principle of isochronism of the pendulum, and then told Li Fu some of the structure of the pendulum clock and asked him to think.

Before Li Ke set off, Li Fu had already eaten this knowledge thoroughly, and even figured out some truths that Li Ke did not tell him.

For example, under the premise of the principle of isochronism of the pendulum, this isochronism is independent of the mass and amplitude of the pendulum.

and the period of vibration of the pendulum is proportional to the length of the cycloid, and inversely proportional to the square root of the gravitational acceleration.

Gravitational acceleration Li Ke has been completely proposed, or several laws of Newton Li Ke have been directly taken out, and these craftsmen always have to learn some truths directly when they come into contact with these.

After he figured out these principles, and he used Li Ke to mention the size of the gear, etc., he also built a simple pendulum clock.

Although it is not as elaborate as later generations, the principle is the same.

After he figured these things out, Li Ke gave him the complete drawing of the pendulum.

It can be said that after figuring out these and getting the complete pendulum drawings, it is only a matter of time before Li Fu understands the entire drawing, and this kind of taught craftsman does not only know it but does not know why.

He has understood many principles and truths, and has the ability to deepen them.

At least Li Ke knew from Tian Meng that Li Fu had spent most of the year studying almost every day, especially mathematics and physics, which were the top priorities of his study.

"How much does it cost us to make a pendulum clock now?" Li Ke asked.

"These parts are very fine, according to our watch factory itself cast parts and ordered from the foundry mainspring and set aside 100% of the profit for the foundry, the cost of making a pendulum clock is about 30 times, and the time is about half a month." Li Fu said.

"How many craftsmen have been trained?" Li Ke asked.

"There are about 400 or so people, and only about 30 of them are worth continuing to train." Li Fu said, "The rest of the people can only reach the point of maintaining and repairing the pendulum clock, and it may be difficult for them to make their own pendulum clock." ”

"30 times." Li Ke repeated, this cost is not high, and the premise of its low is that the cost of steel has been compressed by Li Ke.

"The price of this basic mahogany model is set at 3,000 pieces!" Li Ke pointed to the 20 pendulum clocks that had been made with a height of about 1 meter.

"Later, you will work hard to develop a smaller pendulum clock, the smaller the pendulum clock, the higher the price, in addition, I will start to build a bell tower in the Vermilion Bird Square in Chang'an City, and then a huge pendulum clock will be built on the bell tower, and then the people of the entire Chang'an City can use the time of this bell tower as the standard." Li Ke said.

Suzaku Square is the intersection of Suzaku Hengjie and Suzaku Street, and the front of the Suzaku Gate of the Imperial City of the Tang Dynasty.

"Yes!" Li Fu is a little pressured, such a large bell tower, the weight of the pendulum clock, the length, etc., can be completely calculated, but when it is made, the weight is a little problematic, I am afraid that the time will not be accurate.

"In addition, the wood outside the pendulum clock, such as mahogany, rosewood and other different wood customized prices are also different, the more expensive the wood, the higher the price, and the carpenter can also carve it, the better the carving, the higher the price."

"For example, if the wood is more expensive and the cost increases by 10 guan, you can use the basis of 3,000 guan to increase the newly increased cost by 50 times and sell it for 3,500 guan. If the cost of wood increases by 10 guan, and the carving requires the craftsman to spend another 10 guan, then sell it for 4,000 guan. Li Ke explained to him, "Remember that this is the ex-factory price." ”

"Yes!"

"Well, when the time comes, for example, if my Yuelai firm sells on behalf of us, we will charge a symbolic profit of more than ten yuan."

"The same is true of other comptoirs, which allow them to increase their own profits, but not too much from their sales. However, in the short term, it is unlikely that other firms will sell it. Li Ke said.

"By the way, when the time comes, you will give yourself a name for the clock, and the name should be written on the dial, for example, I will first give one to each department of the three provinces and six departments of the imperial court, you give a name, the six are called the horse series, and the three provinces are called the cow series. When the time comes, it will be used by my father, such as the Yinglong series. Even if it is the same material, this Yinglong series is 1000 times more expensive than this cow and horse series. ”

"Yes...... Do you remember that? Li Fu scratched his head, then looked at a young man behind him and asked.

"I remember." The young man immediately bent over.

"Your Highness, this is the finance of our factory, and I'm too bad at these things." Li Fu was a little embarrassed.

"Well, it's good, leave professional things to professional people." Li Ke smiled, this aspect of finance must have been cultivated by Yuelai Commercial Bank, and it is okay to hand over these things to them, anyway, they can know how to increase profits.

"Remember that if someone asks in the future, you will say that a total of one million yuan was spent on the development of clocks, which is the research and development expenses." Li Ke thought about it and added.

"Ah...... But...... How can Your Highness spend so much on this? "Li Furen is stupid.

That's a million guan, how can it be spent?

"Why can't you spend it all, in order to test the accuracy of the clocks in different places, you sent more than a dozen test teams to different directions in the east, west, north and south of the Tang Dynasty, and these teams are composed of at least a hundred people, and they don't need money to eat, drink, and Lazar? It doesn't cost money to ship the damage of these clocks and watches? Li Ke said helplessly.

"Then I see." Li Fu is not stupid, and if he is not good at it, it does not mean that others do not understand it after saying it.

"By the way, add all our royal warrants. In addition, the clocks in this series are called the Ruzi Niu brand. Engrave a couplet on the pendulum clock. Shanglian: Spring silkworms to the end of the dead silk. Downlink: The wax torch turns to ash and tears begin to dry. Horizontal batch: to serve the people. Don't forget to add our royal logo. How long does it take to get it done? ”

"It's simple, it's all you need in a day." Li Fu said very simply.

"Do it now, I'll do it tomorrow morning. Tomorrow I will go to send warmth to the six departments of the three provinces, speaking of which, I have come back from this Nanyang, and I haven't sent them a gift yet, just right. Li Ke said.

"Yes!"

Coming out of the watch factory, Li Ke called Tian Meng again and asked him to find a craftsman and carve a few plaques.