[An 1899 map of northern Taiwan detailing all towns, big and small, located between Danshui and Keelung; click to enlarge.]
The navigational difficulty of Danshui River and Harbor owing to the sandy deposits has a long history. The following is quoted from Colquhoun, A.R., and J.H. Stewart-Lockhart. "A sketch of Formosa." The China Review (1885): 161-207:
"The harbour [left: an 1893 French map of Danshui Harbor, click to enlarge] is really formed by the debouchure of numerous streams rising in the mountains in various directions, and at distances varying from twenty to seventy miles from the mouth. The main branch comes from the south-east, but another important one rises in the north-east, in the immediate neighbourhood of Keelung, a few miles to the south, on the southern side of a hill-pass, the upper reaches being covered with fierce rapids. These streams flow towards Mêngka, called also Bangka or Banca, where they form a junction, some fifteen miles from the sea, into which they empty themselves. Large quantities of silt are brought down by the river, especially when swollen by heavy rains, the result being a troublesome bank in the middle of the river, and the narrow bar at the entrance, on which the sea at times breaks with great violence. A dangerous surf rises with a fresh breeze, and vessels cannot count on entering, or once within, on leaving the port. In fine weather and at high tide, coasting steamers of small draught can enter, but vessels of any considerable draught do not venture in, on account of the insufficient depth, and the surf-swell. The anchorage has shifted from the southern side, where it was within the memory of native residents, to the northern bank. This has been generally attributed to the wholesale deposit of ballast from junks in the river, never interfered with by the Chinese officials."
Apparently the authors did not realize the "wholesale deposit of ballast..." was in fact a defense against the French fleet consisting of stone-laden ships sunken on order of Liu Ming Ch'uan and later reinforced by Sun Kai-Hua.
The "ballast from junks" was actually red bricks used to stabilize small transport ships sailing across the often stormy Taiwan Strait from China. The bricks were a valuable commodity not to be discarded haphazardly as implicated in the above quote. Once arriving in Danshui, the bricks were sold locally. Many houses in Danshui were constructed with these ballast bricks and some still can be seen today. They are not to be confused with the bricks for the famed Fort San Domingo. The latter were of a different constitution; the Dutch had them shipped in from Batavia (Jakarta, Indonesia).
And of course, in later days, bricks were produced in Taiwan by 台灣煉瓦株式會社 (Taiwan Renga Co) and 撒木耳煉瓦會社 (Samuel and Samuel Co) - the bricks were marked with TR and S (or reversed S), respectively.
Danshui Presbyterian Church, on the other hand, was built with 30,000 "high-quality" bricks imported from Amoy, possibly the same type of bricks used previously in the construction of the villa of oil tycoon 黃東茂. The 黃 residence was located in the area marked "Maisons européennes" in the lower right corner of the French map (see above). The "Europeans" refers to John Dodd and Dr Mackay's missionary colleagues. This area was vacated for the construction of the tiny seaplane airport in 1939. This international airport was bombed on Oct 12, 1944, by the Americans, three years after it opened for business.
黃東茂, nicknamed 五舍 (for 五少爺) was one of the three most wealthy locals of his time (the other two: 許丙 and 洪以南). Only they could afford to join the Danshui Golf Club.