Theories Based on Chinese Concepts
Even discussions of earthquakes based on Buddhist cosmology or Aristotelian views usually employed a Chinese-derived metaphysical vocabulary to explain the workings of heaven and earth. The Chinese text with the greatest influence on theories of earthquakes in Tokugawa Japan was Astronomy Questions Answered (Japanese: Tenkei wakumon; Chinese: Tianjing huowen, 1597). Although mainly about astronomy, the second volume of this work contains a discussion of earthquakes. Astronomy Questions Answered became widely read after 1730, when Nishikawa Seikyū added Japanese reading marks to the classical Chinese text. This work circulated among scholars early in the Tokugawa period, even though technically it was a prohibited book until Tokugawa Yoshimune's reign as shogun (1716–1745). Based on their content, it is clear that several Japanese discussions of earthquakes prior to 1730 relied on the explanation in Astronomy Questions Answered.
Reminiscent of Aristotle's view, Astronomy Questions Answered explains that there are holes or spaces in the earth, similar to the appearance of a bees' nest or the cap of a mushroom. Therein lies concealed the material substance of fire and of water, the violent collision of which produces earthquakes when there is no outlet. The same process produces thunder. Places with sandy or muddy soil such as the North Pole or the equator rarely experience earthquakes. On the other hand, warm, rocky areas are the ideal environment for earthquakes. When earthquakes occur under buildings, it is like an explosion of gunpowder, causing much damage. The force of earthquakes is capable of causing mountains to shift and the surface of the earth to tear. These forces can create new mountains or islands and reverse the flow of rivers. When the violent material force dissipates as heat, the shaking stops.
One classical Chinese book many Japanese authors mentioned is the Classic of History (Shijing), which is the source of the basic idea that rising yang energy causes earthquakes: “When the yang energy is trapped and cannot emerge, or the yin energy represses it and keeps it from rising, then there is an earthquake.” The Classic of History did not elaborate on details such as how the yang energy became trapped, so later Chinese and Japanese books fleshed out this basic idea. Terashima Ryōan began the discussion of earthquakes in his ca. 1712 encyclopedic work, Illustrated Compendium of Chinese and Japanese Knowledge (Wakan sansai zue), by stating “When yang exists below yin and is suppressed by yin, if there is no way for yang to rise upward, an earthquake occurs.” Next, we find a paraphrase of Astronomy Questions Answered. According to “astronomy books,” the earth is like a bees' nest or the cap of a mushroom in that interconnected holes or conduits permeate it all around. Water force and fire force reside in these conduits. When the energy from the accumulation of these forces cannot erupt to the surface, it is like a cramp developing in a person or thunder in the skies. Ryōan explains that extremes of climate result in fewer earthquakes. Far northern lands are so cold that they do not generate heat, and lands below the equator readily dissipate heat because the sun is so strong. In rocky areas at temperate latitudes, by contrast, there are spaces beneath the surface into which hot energy blows and is trapped by cold energy. When this situation surpasses a threshold, an earthquake occurs. Large earthquakes do not cause uniform shaking over a wide area but instead cause localized upwelling of energy. Sometimes the underground energy turns into fire owing to intense heat. After it departs to the surface, the shaking stops.
After conveying the Astronomy Questions Answered explanation of the cause of earthquakes, Ryōan elaborates further. Normally, yin and yang are in balance within the earth, but a blockage of yang leading to its long-term accumulation can cause the earth to expand and water to contract like a rice cake expanding when cooked. Wells can go dry or the water in them becomes warm as a result. Possibly referring to different types of seismic waves, Ryōan points out that when earthquakes strike, the initial shaking is especially severe but the second wave is weaker. He then explains that “black waves [kuronami] . . . commonly known as tsunami,” as high as a mountain can occur when an earthquake stirs up ocean water by the expansion of land. After a large earthquake, lesser shaking can occur for months afterward because the trapped hot energy has not fully escaped. Ryōan explained volcanic eruptions as another manifestation of the same basic situation of hot, yang energy trapped underground. He points out instances in 863/864 and 1707 of Mt. Fuji erupting soon after an earthquake and one case in 800 of an eruption not preceded by an earthquake. In this case, Ryōan speculates that the eruption released all of the underground energy.
Ryōan continues the discussion of earthquakes by pointing out that although all countries exist under the same sky, earthquakes are localized phenomena. An earthquake in China will not be felt in Japan, nor will one in Osaka be felt in Edo, and the severity of shaking varies even within the same village as a function of whether the soil is firm or soft. This last point was an advance in knowledge, and by the end of the Tokugawa period we find variations of this topic in a range of literature. For example, after the 1855 Ansei Edo earthquake, Jōtō Sanjin explained in Account of Broken Windows (Mado yabure no ki), “In the current earthquake, high ground shook and low ground shook severely. The situation is that Azabu, Yotsuya, Hongō, Komagome and nearby high ground shook, and the castle grounds, Ogawamachi, Koishigawa, Shitaya, Asakusa, Honjo, Fukagawa, and nearby areas shook to a greater degree. This is a natural principle [shizen no kotowari].” Even more to the point was Mishima Masayuki in Observations after the Earthquake (Nai no nochimigusa). Walking through Edo in the days following the Ansei Edo earthquake and recording the damage in each area, combined with his knowledge of the city's past, Masayuki pointed out that areas such as “Daimyo Lane” were built on land that long ago had been reclaimed from the ocean. “Such places,” he deduced, “naturally [onozukara] shake more severely in an earthquake.” Modern textbooks point out that ground motion is most severe in the case of unconsolidated fill, owing to an increase in wave amplitude, a vertical shift in the path of seismic waves, and because waves are trapped by basement rock.
The final point in Ryōan's discussion is instructions for a simulation that “might seem to be child's play, but very closely simulates the basic logic of earthquakes.” In a bucket, pile up some rough sand with a spout at the bottom and add water. Several people in rotation blow air through the spout. Initially the air does not emerge because yin has trapped yang. Eventually the bucket will shake. When the air has escaped, the shaking will stop. Explicitly citing Illustrated Compendium of Chinese and Japanese Knowledge, the popular 1856 work Ansei Record (Ansei kenmonroku) included this same simulation.
The observations Ryōan passed along concerning seismic waves and varying degrees of ground motion in different localities and soil bases were potentially valuable contributions to an emerging science of earthquakes. The precision of the empirical observations of some Tokugawa-period writers was remarkable. For example, Kokuryōki, an account of conditions in the Tosa domain in Shikoku following the powerful 1707 Hōei earthquake, contains the following entry: “After the great earthquake, the contour of the earth [chikei, topography] rose at the harbors of Tsuro and Murozu in Aki-gun. Last year, large ships full of cargo could enter the port freely, but after the disaster, large ships full of cargo were unable to enter. Because this port was cut from rock, the bottom consists of rock, so it is not a case of mud filling in the bottom. [This change] is proof that the contour of the earth has risen.” Uplift and subsidence were common occurrences in ocean trough (Tōkai and Nankai) earthquakes such as Hōei.
Another influential work that relied heavily on Chinese theories was Nishikawa Joken's 1715 analysis of heavenly and earthly phenomena, Strange Phenomena Explained (Kaii bendan). The work consists of four “heaven” volumes and four “earth” volumes, with earthquakes discussed as the first topic in the first earth volume. The initial paragraphs cite Chinese sources from ancient times through the Ming dynasty, including the Classic of History explanation of accumulated yang trapped by yin as the cause of earthquakes. Some of the passages provide analogies between natural phenomena and human phenomena. For example, Strange Phenomena Explained likens the shaking of the earth to disordered relations between rulers (yang) and ministers (yin) and the resulting upheavals. Several passages also mention specific large earthquakes in China and the extent of casualties they caused. Following these Chinese accounts is a brief record of early Japanese earthquakes between 845 and 870.
Joken's own analysis (the bendan) then begins with the observation that only accounts of major earthquakes are found in the historical record, and these events are rare in both China and Japan. Taking up the common Chinese idea that astrology can predict earthquakes, Joken argues that destructive earthquakes may occur so suddenly that predicting or divining them is impossible. In the classical process of divination, earthquakes occurred by yin filling in a loss or absence of yang, and therefore the vigorous activity of ministers of state was one possible indication of an impending earthquake. If, however, we follow the explanation in the Yellow Emperor's Classic of Medicine, the action of wind causes earthquakes. Wind is yang energy that finds its way into the earth and seeks to flow and expand. Earthquakes happen when yin energy suppresses this wind. After discussing an analogous process as a cause of illness within the body, Joken declares that the wind theory and the theory of yin filling in for absent yang are substantially the same. Next, he mentions the Buddhist idea of the earth sitting atop a layer of water, which wind can agitate to the point of causing the earth to shake. He concludes that the Buddhist theory is largely the same as the causal mechanism mentioned in Yellow Emperor's Classic of Medicine.
Joken's next topic is the popular notion of an “earthquake fish” (jishin no uo). By 1715, the specific association of catfish (namazu) and earthquakes had developed, especially in the area around Lake Biwa, but catfish had not yet become a widespread symbol of earthquakes. By the early eighteenth century, the general idea or metaphor of some sort of giant dragon, serpent, mushi (worm/insect), fish, or other creature moving about under the earth was common in Japanese folklore. Joken points out that fish are yang creatures living within a yin environment. Therefore, their association with earthquakes was probably because fish could serve as a metaphor for the Buddhist notion of wind (yang) agitating water (yin). “In any event,” Joken concludes, “this notion is far from correct principles.” After taking up the fish topic, Joken concludes the section on earthquakes by mentioning a country named “Berū” (Peru), located to the southeast of Japan, which is subject to many severe earthquakes. Moreover, there are reports of many other countries in the world in which earthquakes are frequent. He may have mentioned the occurrence of earthquakes in other countries immediately after the fish discussion because most folklore about an earthquakecausing creature imagined it to be located under Japan.
The next section is entitled “Fissures in the Earth and Fissures in Mountains,” two conditions caused by large earthquakes. Here too, Joken begins with specific examples from classical Chinese sources followed by Japanese sources. His own analysis states that these phenomena follow the same logic as earthquakes, namely that yang energy in the earth provides the force to break apart earth and rocks owing to the shaking. Joken then points out the phenomenon of liquefaction, whereby mud sometimes issues from cracks in the earth. His final point is that “something resembling ash” sometimes also issues from these cracks, depending on the situation of the earth at that location. Joken's discussion of earthquake-related phenomena continues in sections entitled “Subsidence of the Earth and Mountains,” “Collapses of Mountains,” “The Emergence of Flat Land and Islands,” “The Movement of Mountains, Mounds, and Islands,” and “The Groaning of Mountains.” These sections follow the same approach as the ones examined thus far: examples of specific cases from classical texts, an analysis based on the basic idea of yang in the earth seeking to escape upward, and mention of the phenomenon in places other than Japan and China.
Joken published a similar eight-volume work in 1712, Discussions of the Heavens (Tenmon giron; also known by the title Ryōgi shūsetsu). In this earlier work, his basic theory of earthquakes is the same as Strange Phenomena Explained. One difference is that the earlier work paraphrases Astronomy Questions Answered in several places. Joken's major accomplishment in these works was to synthesize Buddhist, Western, and Chinese ideas about earthquakes and apply a basic causal mechanism to explain a wide variety of earthquake-related phenomena. The general idea that imbalances in yin and yang were the physical mechanism causing the earth to shake became the ordinary, commonsense understanding of earthquake mechanics during the eighteenth century.
In the broader perspective, the idea that yang accumulates in the earth and moves upward toward the sun functioned as more than an explanation for earthquakes. This idea was a foundational concept in many general theories of the earth. Miura Baien, for example, explained in the middle of the eighteenth century that the ground is a concentration of yin energy from which yang emerges. Under certain circumstances, this upwelling of yang breaks up the earth's surface, thus creating areas for water to accumulate. Indeed, a complex interplay between yin, yang, and its five agents explained the composition and movements of the earth, moon, and sun for Baien and many other Tokugawa intellectuals. Let us now move into the nineteenth century to examine several influential texts.
The 1830 Kyoto earthquake caused several hundred deaths and several thousand injuries, and it was followed by an unusually large number of aftershocks. It was the first major earthquake to shake the imperial capital in living memory. Major earthquakes had sometimes shaken Kyoto much earlier, and Asai Ryōi's Foundation Stone describes in detail the destruction to the city in 1662 following the stronger and more deadly Kanbun earthquake. Although the 1662 event was more powerful and destructive, the 1830 earthquake seems to have generated more social anxiety. One reason was the timing. It was an okage year, featuring popular religious pilgrimages with millenarian overtones. Whereas the Kanbun earthquake shook a wide area including Kyoto, the 1830 earthquake shook mainly the city itself. Most important, the popular press was much more prominent than in 1662. Competition for sales of prints and ephemera resulted in exaggerated reports of death and destruction. This coincidence of circumstances garnered much attention throughout Japan for the 1830 Kyoto earthquake. Among its many products were two influential books.
The more important book was Thoughts on Earthquakes (Jishinkō).
Kojima Tōzan wrote it with the explicit purpose of calming fears of a breakdown in social order by explaining earthquakes in a rational manner. Although “Tōzan sensei” appears prominently on the cover as the author, the book appeared after his death. Tōzan indeed wrote the first half, but an anonymous student, known only by his pen name Tōrōan-shujin, wrote the more interesting second half.
Thoughts on Earthquakes begins with a basic description of the earth-quake that had just shaken Kyoto. It points out that the shaking damaged or destroyed many storehouses and earth embankments and some houses, and injured many people. Tōzan explains that while events like this had happened long ago, nothing on such a scale has taken place in recent years. “People are shocked and terrified.” To reassure readers, Tōzan quotes a proverb: “Earthquakes are severe at the beginning, typhoons are at their worst in the middle, and thunder is dramatic at the end.” The point, of course, is that the worst is now behind us. Next, “for the purpose of calming people,” he noted that “since antiquity, historical records in Japan have recorded the occurrence of earthquakes.” His first example is from 887, and the context of subsequent examples indicates that they are all earthquakes that shook Kyoto. Unlike the worldwide scope of authors such as Nishikawa Joken, Tōzan's approach was to normalize the 1830 earthquake by putting it into the context of a long line of such events affecting the imperial capital. Another calming function of these examples was to point out that aftershocks, indicated by counts of the number of times shaking occurred, are a normal part of earthquakes. At the end of the section, Tōzan explains that in each series of shaking he described, the first instance was always the most severe and the intensity decreased afterward.
The next section is a basic explanation of earthquakes, and it contains little that was new at the time. The first statement is that earthquakes occur when yang energy within the earth seeks to rise but is trapped by yin energy. The next paragraph cites Astronomy Questions Answered and explains that there are holes in the earth like a bees' nest or the cap of a mushroom and that the contact of fire and water creates a force that seeks to rise and causes the earth to shake if blocked. Next is the familiar geographical information whereby the cold extreme north and hot equatorial areas as well as areas of sandy or muddy soil experience few earthquakes. By contrast, warm areas with rocky soil suffer the highest frequency of earthquakes. The gunpowder analogy of Astronomy Questions Answered got a slight upgrade in Tōzan's account, becoming the blast of an old-style cannon.
The explanation of the causal mechanism of earthquakes is brief, and a longer section on the signs of earthquakes follows. This point segues into folklore concerning fish and earthquakes. Na refers to a fish (uo), and e refers to shaking (yuri). Nae, the old name for earthquakes, therefore, may have derived from the metaphor of a captured fish vigorously shaking. Tōzan's language clearly indicates the metaphoric nature of the fishearthquake connection, which he describes as “truly the explanation of a small child.” He then turns to the topic of an illustrated almanac from 1198 featuring an “earthquake insect” looking like a giant centipede surrounding all the provinces of Japan (fig. 2). This item is now widely regarded as a seventeenth century forgery, although Tōzan would not have known. He points out that in Buddhist explanations, dragons were linked with
Figure 2 The “earthquake insect/caterpillar” (jishin mushi) as it appears in Thoughts on Earthquakes (Jishinko, 1830). An icon of Mt. Fuji appears in the center of the provinces it encircles.
earthquakes much like fish were in Japan. In any case, he says, there is a variety of old lore about earthquakes. Tōzan's section of the book ends by stressing that in the “current peaceful age,” this earthquake is not a sign of anything greater than itself and that people should put their minds at ease and devote themselves to their duties.
A student of Tōzan wrote the second half of Thoughts on Earthquakes, which begins by explaining that many false theories continue to circulate, aftershocks (shōdō) have not ceased, and people fear that another large earthquake might soon occur. He points out that large earthquakes have been recorded in China and Japan from ancient times to close to the present. Therefore, earthquakes are expected occurrences, portending no future harm. Moreover, most of the current destruction has been damage to property such as storehouses, with relatively little loss of life.
The substantive discussion includes observations about ground motion, the center and periphery of earthquakes, and additional discussion of indications that an earthquake is about to occur. The author first states that the earth is 90,000 Chinese ri in circumference, or 15,000 Japanese ri. The distance from the center of the earth to the surface is approximately 2,500 Japanese ri, and the current earthquake shook an area only 200 ri across. The areas of shaking in any earthquake are actually quite small relative to the vast size of the earth. The author cites Astronomy Questions Answered for the basic idea but supplements it with additional observations.
Next, he explains that earthquakes have a center (shin), where the shaking is most severe. The shaking propagates outward from the center in all directions, getting weaker as a function of distance. In the case of the current earthquake, Kyoto was the center, and the outer edges were Musashi in the east, Kii in the south, Echizen in the north, and Chūgoku and Shikoku to the west. The earthquake did not come from the west or east but radiated outward from the center. One reason for this observation is that people reported seeing smoke rise from the center of the city just as the earthquake began. Materials produced in the aftermath of the Ansei Edo earthquake often drew on Thoughts on Earthquakes, with or without explicit attribution,
and the material on earthquake centers was especially influential. Ansei Record, for example, reproduced the entire discussion, including the diagram. Ansei Record made repeated reference to Thoughts on Earthquakes, as did Ansei Chronicle (Ansei kenmonshi) and catfish prints.
The discussion of earthquake-related lore is similar to that of the first part of the book. The initial topic is the original name for earthquakes in Japan and the notion of earthquake-related creatures, including a fullpage illustration of an Ise Almanac (Isegoyomi) featuring the earthquake “insect” encircling Japan. Toward the end of the book, the author revisits previous theories of earthquakes. For example, he takes up the idea of wind as a possible cause of earthquakes and quotes from Nishikawa Joken's Strange Phenomena Explained regarding this matter. An afterword written by another student in classical Chinese reiterates many of the previous points: that in the past, major destructive earthquakes have been so powerful as to alter the landscape; that currently, Kyoto is experiencing many unnerving aftershocks (yoshin); and that there are specific warning signs of an earthquake. The ultimate message, of course, is that the worst is past, and there is no need for panic or fear of what might occur in the near future.
Although written mainly to promote calm, Thoughts on Earthquakes also advanced seismological knowledge, particularly with respect to the idea of an earthquake center. The diagram features a circle representing the earth (fig. 3). Jishin (earth + center), a homophone for earthquake, indicates the center of the earth. Directly above it, a small circle at the surface indicates the epicenter of an earthquake. Two small dots, one on each side of the epicenter represent the range of shaking. The phenomenon of aftershocks, in this case called yoshin, the same term that is used today, received extensive attention. We have seen that earlier authors were aware of such phenomena as liquefaction and differences in ground motion depending on the soil base. With respect to causes of earthquakes, however, we see find no new ideas in Thoughts on Earthquakes compared with works from the early eighteenth century. By 1830, yin-yang based explanations of earthquake mechanics had overwhelmed alternative theories.
The Kyoto earthquake also produced a small book called Record of Earthquakes in Japan (Honchō jishinki), likewise written with the explicit purpose of calming the fears of both local residents and people in distant parts of Japan who might have been alarmed by the lurid press reports of massive destruction in the imperial capital. Record of Earthquakes in Japan includes a brief explanation of the causes and warning signs of earthquakes. The work begins with an interesting overview of geography: “The body of the earth is yang in the north and yin in the south. Most mountain ranges are in the north. The body of heaven is yang in the south and yin in the north. Therefore, the sun moves toward the south. This is the overall pattern of heaven and earth moving relative to each other.” Next is the familiar explanation of the cause of earthquakes: yang energy seeking to rise but trapped by yin. Moreover, the earth is like a bees' nest, full of holes that allow fire and water to come into contact. The subsequent discussion includes a list of earthquake precursors such as well water becoming muddy and mountains appearing closer. In short, there is nothing distinctive about the explanation of earthquakes or their warning signs in this work.
What distinguishes Record of Earthquakes in Japan from Thoughts on Earthquakes and other discussions of earthquakes is the inclusion of a comprehensive list of the recorded earthquakes in Japan to date, in chronological order. The earliest example is an “earthquake followed by rain” in 645. Hashimoto Manpei regards Record of Earthquakes in Japan as the
Figure 3 Diagram of the earth's center, the epicenter of an earthquake (top small circle) , and the range of shaking (two black dots), from Thoughts on Earthquakes (Jishinko, 1830).
earliest earthquake history in Japan, and it was indeed comprehensive. As we have seen, however, nearly all discussions of earthquakes from the seventeenth century onward provided select chronologies of major past earthquakes. Record of Earthquakes in Japan is distinctive only in the thoroughness of its compilation.
-  Baba Nobutake, for example, used language almost identical to Tenkei wakumon in his 1706 Shogaku tenmon shinan. See Hashimoto, Jishingaku, 14–15.
-  Although gunpowder served as a metaphor in Tenkei wakumon, several later Japanese scholars of Dutch studies proposed actual gunpowder as a possible cause of earthquakes. For example, Kawamoto Kōmin’s Kikaikanran kōgi, published soon after the Ansei Edo earthquake, proposed two theories of underground combustion, one of which was that heated oxygen ignites saltpeter, charcoal, and sulfur located near the focus of an earthquake. Another book published after the Ansei Edo earthquake was Hirose Genkyō’s Rigaku teiyō, based on his reading of several Dutch books. He proposed that saltpeter, charcoal, and sulfur under the earth explode to create earthquakes. See Hashimoto, Jishingaku, 36–38, and Nihon gakushiin, Butsuri kagakushi, 552–553.
-  Tenkei Wakumon, vol. 2, “Jishin” (Osaka: Ōsaka shobō, 1794 revision of the 1730 edition), manuscript, 28–29 (four pages). See also Hashimoto, Jishingaku, 13.
-  Sima Qian, Shijing, Zhoubenji, King You 2, entry 36. William H. Nienhauser Jr., ed., Tsai-fa Cheng et al., trans., The Grand Scribe’s Records, vol. 1: The Basic Annals of Pre-Han China by Ssu-ma Ch’ien (Bloomington: Indiana University Press, 1994), 73. For the original text, see http://ctext.org/shiji/zhou-ben-ji
-  Terashima Ryōan, Wakan sansai zue, vol. 8, Shimada Isao, Takeshima Atsuo, and Higuchi Motomi, trans., eds. (Heibonsha, 1987), 9.
-  Terashima, Wakan sansai zue, 9–10.
-  Terashima, Wakan sansai zue, 11. Although even today it is common for many people to assume a connection between earthquakes and volcanic activity, scientists have not been able to establish any direct link. For a basic explanation, see Shimamura Hideki, Nihonjin ga shiritai jishin no gimon rokujūroku: Jishin ga ōi Nihon dakara koso chishiki no sonae mo wasurezu ni (Sofutobanku kurieitibu, 2008), 90–92.
-  Terashima, Wakan sansai zue, 12.
-  Quoted in Nakamura Misao, “Ansei Edo jishin,” in Chūō bōsai kaigi, 1855 Ansei Edo jishin hōkokusho (Fuji sōgō kenkyūsho, 2004), 6. Nakamura points out that by 1855, experience from other earthquakes had promoted an understanding of soil base as a major factor in the intensity of shaking. See also “Yabure mado no ki,” in DNJS, vol. 2 (otsu), 561.
-  “Nai no nochimigusa,” in DNJS, vol. 2 (otsu), 572.
-  See, for example, Susan Elizabeth Hough, Earthshaking Science: What We Know (and Don’t Know) about Earthquakes (Princeton, NJ: Princeton University Press, 2002), 80–83.
-  Terashima, Wakan sansai zue, 12.
-  “Chika yori kaki o hassuru no jō,” in Hattori Yasunari (text) and Utagawa Yoshiharu (illustrations), Ansei kenmonroku (hereafter AKR), vol. 2, 12. See also Arakawa, Jitsuroku, Ō-Edo kaimetsu no hi, 89.
-  “Kokuryōki,” in DNJS, vol. 1 (kō) (Shibunkaku, 1973), 324. In this case, ships unable to dock at Tsuro and Murozu were able to dock at Kōchi for the first time because of approximately two meters of subsidence in the area. See Okada Yoshimitsu, Saishin Nihon no jishin chizu (Tōkyō shoseki, 2006), 169–170.
-  Nishikawa Joken, Kaii bendan, vol. 5 (Kyoto: Ryūshiken, 1715). First four page faces after the heading “Jishin” deal with China; next two-plus page faces deal with Japan.
-  Nishikawa, Kaii bendan, vol. 5, page faces 8–12 after the heading “Jishin.” See also Nihon gakushiin, Butsuri kagakushi, 538–539.
-  For a detailed examination of this and related matters, see Smits, “Conduits of Power,” 41–65.
-  Nishikawa, Kaii bendan, vol. 5, page faces 12–14 after the heading “Jishin.” See also Nihon gakushiin, Butsuri kagakushi, 539. The later transcription spells the earthquake-prone country as “Beruru,” but it is clearly “Berū” in the original.
-  Nishikawa, Kaii bendan, vol. 5, page faces 1–2 after the heading “Chiretsu oyobi ni yama-sakuru.”
-  Nishikawa, Kaii bendan, vol. 5, page face 3 after the heading “Chiretsu oyobi ni yama-sakuru.” See also Nihon gakushiin, Butsuri kagakushi, 539.
-  Nishikawa, Kaii bendan, vol. 5.
-  Nihon gakushiin, Butsuri kagakushi, 540–550.
-  Miura, Zeigo, 421.
-  Kojima Tōzan and Tōrōan-shujin, Jishinkō (Kyoto: Saiseikan, 1830), first two page faces in the second section of the book, and Hashimoto, Jishingaku, 22–24.
-  Kojima, Jishinkō, page faces 1–3 after the heading “Jishinkō” describe the 1830 earthquake and printed page faces 3–8 describe past earthquakes. “Jishinkō,” in DNJS, vol. 1 (kō), 589–590. See also Hashimoto, Jishingaku, 23–24, and Nihon gakushiin, Butsuri kagakushi, 562–563.
-  Kojima, Jishinkō, page faces 1–4 after the heading “Jishin no setsu.” “Jishinkō,” in DNJS, vol. 1 (kō), 590.
-  See, for example, Unno Kazutaka, “Maps of Japan Used in Prayer Rites or as Charms,” Imago Mundi 46 (1994), note on 76.
-  Kojima, Jishinkō, final two page faces in the section “Jishin no shirushi.” A jishin mushi illustration appears the second part of the book. “Jishinkō,” in DNJS, vol. 1 (kō), 591 (no illustrations). See also Hashimoto, Jishingaku, 24. To view the illustration, see figure 2.
-  Kojima, Jishinkō, page faces 1–2 in the second section. “Jishinkō,” in DNJS, vol. 1 (kō), 591. See also Hashimoto, Jishingaku, 24.
-  That the earth is a sphere was common knowledge throughout the Tokugawa period. Ancient Greek mathematicians proved that the earth was a sphere, and around 240 BCE, Eratosthenes calculated the circumference of the earth to a high degree of accuracy. The idea of a spherical earth later spread to India and the Islamic world, where scholars quickly accepted it. In China the idea did not become firmly established until the Ming dynasty, in part owing to the work of Jesuit priests. In Japan, there were explicit debates about the shape of the earth and heavens during the first decade of the seventeenth century. Kyoto was a center for astronomy, and Carlo Spinola established a mathematics and astronomy academy there in 1611. See Sugimoto Isao, ed., Kagakushi, Taikei Nihonshi sōsho 19 (Yamakawa shuppan, 1976), 136.
-  In most accounts, earthquakes simply occur, but sometimes they arrive from a particular direction. For example, from within Kyoto, Asai Ryōi described the Kanbun earthquake as arriving from the northeast. See Kaname’ishi, 15. A diary describing the 1847 Zenkōji earthquake stated, “An earthquake arrived from the west.” See “Koizumi Sōken nichiroku,” in NRJSS, vol. 2, 226.
-  Kojima, Jishinkō, page faces 2–5 in the second section. The third page face consists of an illustration of the earthquake center. “Jishinkō,” in DNJS, vol. 1 (kō), 592 (no illustration). See also Hashimoto, Jishingaku, 24–25, and Nihon gakushiin, Butsuri kagakushi, 563. To view the earthquake center illustration, see figure 3.
-  See “Jishin no hōkaku o iu jō,” in AKR, vol. 2, 17–18 (final three page faces). See also Arakawa, Jitsuroku, Ō-Edo kaimetsu no hi, 69–71. To view the diagram, see http://archive.wul.waseda.ac.jp/kosho/wo01/wo01_03628/ wo01_03628_0002/wo01_03628_0002_p0022.jpg.
-  Kojima, Jishinkō, page faces 10–12 in the second section. “Jishinkō,” in DNJS, vol. 1 (kō), 593 (no illustration).
-  Kojima, Jishinkō, page face 16 in the second section.
-  Ibid., section entitled “Daijishinkō no ato.”
-  Ibid., page face 3 in the second section. To view the diagram, see figure 3.
-  In examining the broad discourse on earthquakes, which includes hundreds of minor works, one can occasionally find variations on this idea. For example, one minor text from 1855 or 1856 explains that yin rising upward from out of the earth becomes rain, clouds, or in extreme cases, thunder and lightning. Conversely, yang entering the earth from the sun, in extreme concentrations, causes earthquakes. See “Ansei ni Edo jishin,” in NJS, vol. 5, supplement 2 (Ansei Edo jishin), part 1, 575.
-  Toyo Tokinari, Honchō jishinki, in Edo josei bunko, vol. 49 (Ōzorasha, 1994), no pagination. See the final page face. The discussion of the causes and warning signs of earthquakes can be found in Kojiruien (an encyclopedic work published between 1896 and 1914), 1359 in “Chibu” (available today via the Kojiruien Database, International Research Center for Japanese Studies: http://shinku.nichibun.ac.jp/kojiruien/). See also Hashimoto, Jishingaku, 26–27.
-  Toyo, Honchō jishinki, first page face of the main text, and Kojiruien, 1359 in “Chibu,” entry “Jishin.” This same description occurs in the similarly titled 1855 Honchō jishin no shidai. See DNJS, vol. 2 (otsu), 584 and FN, 563.
-  Toyo, Honchō jishinki, page faces 2–6 from the start of the main text, and Kojiruien, 1359 in “Chibu,” entry “Jishin.”
-  Toyo, Honchō jishinki. Page faces 7–25 from the start of the main text (including the illustrations) constitute the survey of earthquakes up to 1830. See also the comprehensive listing of major historical earthquakes in the “Jishin” section of Kojiruien under the subheading “Jishin rei,” 1366–1375.
-  Hashimoto, Jishingaku, 26.