COAST OF OREGON AND CALIFORNIA. 



331 



The South Sandspit overlaps the North, extending beyond it to the 

 west. They have been formed by deposits of sand brought down by 

 the current of the river, and from the abrasion of the capes by the 

 sea ; the water being checked by the ocean, causes the, sand, which 

 it held suspended, to be deposited. Whilst this cause continues, it 

 must result in constant changes to the channels, and the shifting or 

 increase of the bar. 



The greater part of the mouth of the Columbia is occupied by 

 a sand island and the spits above mentioned. They are daily under- 

 going changes, although composed of hard sand. The former occupies 

 the middle of the river. 



The bar lies 1 mile outside of the spits. On it there is from 4 to 4 i 

 fathoms depth of water. There is no danger or risk in passing it 

 when the sea does not break. 



On both spits there are usually heavy breakers on the flood ; but 

 there are times when there is little or no break on either spit. 



The south end of the North Spit has to be closely approached, if 

 intending to take the old channel into Bakers Bay. This is the 

 point of greatest danger, and here most of the accidents have hap- 

 pened to vessels and boats entering the river. The cross-tides to 

 which a vessel is subjected, their velocity, the influence of an under- 

 current, together with a heavy swell and oftentimes the loss of the 

 breeze, renders this point and part of the channel exceedingly diffi- 

 cult. The leading marks are so distant that they are of little use 

 in guiding a vessel ; but when they become indistinct from the misti- 

 ness of the weather, it is attended with great danger. Although 

 the channel has materially changed since the survey of the Columbia 

 River by the Expedition, it may yet be useful to give the precautions 

 and sailing directions which I drew up at the time, in order to 

 show the changes which have taken place, and may be expected to 

 occur. 



It is safest to enter the river on the ebb tide, with the westerly 

 wind, which sets in about 10 or 11 o'clock A.m., during the summer 

 months. As a general rule, the entrance should never be attempted 

 with a flood tide and northwest wind, unless the Clatsop Channel is 

 used and the sea is quite smooth. After making Cape Disappoint- 

 ment, if to the southward, lead in for it on a northeast bearing ; if 

 to the northward, stand in until you have that bearing on. A saddle 



