Chapter 376 - Verification Pendulum Mark I

The crude precision of the fit caused the pin to make a “clatter-clatter” sound as it interacted with the escapement fork. This wasn’t the main problem, as it was, after all, a test model.

The Yuanlao serving in the Ministry of Science and Technology came one after another to see this primitive pendulum system, offering their suggestions for improvement, especially regarding materials and processing. Following their advice, Dr. Zhong redesigned and improved some of the components, which increased the overall operational reliability.

To keep the pendulum a secret, the wooden platform was completely enclosed with tightly fitted wooden boards. In the hot and humid climate of Lingao, the environment inside was like a steamer.

This time, Zhong Lishi did not use the Mongolian strongman Bat as the power source. Instead, he designed a winch on the ratchet wheel’s axle, with a sack of sand hanging below it. The sandbag served as the weight for power. Bat’s duty was now to carry several 25-kilogram sandbags up the 10-meter-high clock tower. The moment Zhong Lishi released the sandbag, the escapement fork was struck by the ratchet wheel, its tail losing balance and slowly beginning to swing, triggering the first escapement impulse. As more and more of the ratchet wheel’s force was transferred to the pendulum, the amplitude of its swing gradually increased until it maintained a stable angle, driving the escapement fork to work rhythmically. The ratchet wheel began to turn step by step with the swing of the pendulum.

This simple wooden prototype marked the beginning of Lingao’s clockmaking industry. It adopted the pendulum regulator invented in 1656 and the free escapement mechanism invented in 1765. Looking at the successfully operating Test Apparatus No. 3, Zhong Lishi thought of Galileo, who discovered the law of isochronism of the pendulum, and couldn’t help but shed tears. At this moment, the venerable Galileo should be suffering persecution from the Roman Curia, in deep water and scorching fire. When Zhong Lishi emerged from the deep water and scorching fire of the test tower, looking as if he had just stepped out of water, people didn’t notice his tears. Only Zhong Xiaoying, when bringing her father dinner, noticed his low spirits and melancholy.

“Father…” Zhong Xiaoying placed her hand on Dr. Zhong’s shoulder, “You are unhappy…”

“Hmm… I was thinking of someone…”

“A senior… a master…” Dr. Zhong said, involuntarily grasping his adopted daughter’s hand—it was soft and warm, which soothed his mood.

Based on Test Apparatus No. 3, Zhong Lishi installed a set of gears to realize the relationship between the minute and hour hands, redesigned the pendulum’s length, and calibrated its period. He also added more sandbags and a winding mechanism with a backstop ratchet. Thus, a usable Test Apparatus No. 4 was born.

On the foundation of Test Apparatus No. 4, Zhong Lishi designed and trial-produced a complete clockwork for a clock tower. The clockwork was made of bronze to ensure performance. Some elastic components were made of phosphor bronze. As this was a prototype, all parts were individually machined by the Yuanlao of the Ministry of Science and Technology themselves, while some were sent to the machine shop to be made by specialized Yuanlao. Of course, there was no concept of tolerance control—for a considerable period, each clock tower clockwork was unique, and each had slight improvements.

While the clockwork was being manufactured, the Lingao Construction Company built an experimental clock tower with a brick arch structure that had excellent shielding and ventilation for it. The clock tower was located on the west side of the Taibai Observatory and later became the site of the clock workshop.

Zhong Lishi personally presided over the installation. This clockwork was named Type YZB-1, also known as “Verification Pendulum Mark I”. The “Verification Pendulum Mark I” clockwork only had a timekeeping function, with just minute and hour hands. To improve operational stability, the hands were counterweighted at the tail to ensure the pivot was the center of gravity. This way, the hands would not affect the clockwork due to eccentricity when rotating on the clock tower’s facade.

Three “Verification Pendulum Mark I” units were built in succession, each with some modifications. A large clockwork is different from a watch, so Zhong Lishi made some attempts that differed from watch design. In the power section, he installed the driving wheel that provided power at different positions in the gear train to compare the advantages and disadvantages of these installation methods. For the escapement fork, the pallets and the ratchet wheel were the parts with the most frequent friction. In a watch, the escapement fork pallets are made of ruby, which is more wear-resistant than the ratchet wheel, because it is more convenient to replace the ratchet wheel than the pallets. For a large clockwork, however, the pallets are large and easy to replace, while a large ratchet wheel is very expensive. Therefore, Zhong Lishi tried using a material slightly softer than the bronze ratchet wheel to make replaceable pallets for the clock tower’s clockwork, in order to protect the more expensive ratchet wheel.

The power for the “Verification Pendulum Mark I” came from four sets of weights, wound separately by four chain-driven winding wheels. The purpose of using multiple weights was to mitigate the change in torque on the clockwork during winding and reduce the impact of winding on timekeeping accuracy. The winding wheel was twice the diameter of the weight’s driving wheel, a design intended to save effort during winding. The driving wheel had a backstop ratchet similar to that on a bicycle’s rear wheel, allowing it to be wound only counter-clockwise (the working direction of the weight wheel was clockwise). The power of a large clockwork is quite strong, so during maintenance, all weights needed to be released to ensure the safety of the maintenance personnel. To prevent accidental falling of the weights, one could not stand underneath them, similar to the principle of “do not stand under a crane boom.”

After a month of testing, the three “Verification Pendulum Mark I” clockworks were officially put into use. Originally, Dr. Zhong had not intended for these experimental models to enter the practical stage, planning only to keep the one installed in the experimental clock tower for teaching and demonstration. But the Planning Commission believed that since they had already been built, it would be too wasteful to scrap them: the production of these three clockworks had consumed a large amount of the Yuanlao technicians’ working hours. Thus, two of them were officially installed in the vacant clock towers. The “Verification Pendulum Mark I” had only one clock face and no lighting. A night illumination system was later added through modification.

It turned out that the bronze clockworks had a long lifespan. Despite some minor issues, they ran normally with good maintenance. These three “Verification Pendulum Mark I” clockworks were only replaced after thirty years of continuous operation. As the progenitors of the Song-Australia clock industry, they became treasures of the museum.

Zhong Lishi made some major modifications to the fourth clockwork: he designed two synchronized clock faces for it and a simple hour-striking mechanism to ring a bronze bell on the hour. This simple time-reporting device could only produce a single chime. This type of clockwork, which could barely report the time, was called “Verification Pendulum Mark II”.

The “Verification Pendulum Mark II” had just been installed in the experimental clock tower and was undergoing testing. However, Dr. Zhong was not satisfied with this clockwork, seeing it only as a validation of his ideas.

“Has the clock chimed every hour?” Zhong Lishi looked at a clock in his workshop. This clock had a very contemporary style for this era: a porcelain clock face, a wooden case, and brass hands. It was indeed assembled by the Ministry of Science and Technology’s clock workshop. But inside was a quartz movement from another time.

A wire protruded awkwardly from the back of the clock, connected to a wooden box. Inside the box was Dr. Zhong’s invention, the “Zhong’s No. 1” battery. Lingao had no dry cells, so quartz clocks had to be powered by external batteries.

In the old world, quartz clocks were synonymous with cheap goods, with ordinary finished clocks retailing for only a few dozen yuan. But in terms of timekeeping accuracy, they completely outmatched any mechanical watch. The Yuanlao Senate had procured a large quantity of timekeeping equipment before D-Day, including not only finished clocks and watches but also a large number of spare parts. A large portion of these were quartz clock movements and quartz oscillators. The cases were made in this time to save space on the ships.

These locally assembled quartz clocks were distributed in important workshops that required precise timekeeping. As controlled materials, each quartz clock had a serial number, and no one except Yuanlao and authorized Ministry of Science and Technology staff was allowed to touch them.

The reason Zhong Lishi attached such importance to quartz clocks was that they were the most accurate timekeepers they possessed. A timekeeping system needs a precise calibration instrument as a reference. He had initially suggested purchasing a large number of quartz oscillators with the intention of using them to build a reference calibration instrument in this time, using the imported semiconductor components to make amplifiers before the electronic components failed.

Dr. Zhong’s plan was to use the quartz calibrator as the master reference, then manufacture a batch of high-precision mechanical calibrators. The locally made clocks would be calibrated using these mechanical calibrators. This hierarchical calibration system was crucial for maintaining timekeeping accuracy. In the old world, radio time signals from broadcasting stations were the main method of time calibration. Lingao could not yet popularize this system and had to use calibrators.

“Yes, your daughter has listened every hour. It has chimed every time,” Zhong Xiaoying said respectfully, presenting a clipboard on which the exact time of each chime was precisely recorded.

Zhong Lishi looked at it. Each chime was slightly delayed compared to the time displayed by the quartz clock, some by as much as one or two seconds. This wasn’t just a matter of the speed of sound—he had tested it after installing the clockwork, and the timekeeping error wasn’t this large. Clearly, there were still some problems with the mechanical transmission of the striking mechanism.

“The transmission still has problems,” Dr. Zhong muttered, putting down the clipboard. He looked at the rain outside, which showed no sign of abating. It seemed that inspecting the clockwork would have to wait until tomorrow.

He wrote a line on his notepad: Build a covered corridor between the workshop and the experimental clock tower.

It was now eleven o’clock. Zhong Lishi planned to go to the Taibai Observatory at midnight to calibrate the time. There was still a little time left. Dr. Zhong looked at the pile of parts and drawings on his desk and decided to continue the trial production of the mechanical calibrator first.