43 
eeed L-32 of an inch 2 inches from the center. The wood is very Light, 
weighing only from 10 to 22 pounds per cubic foot.* 
In the photomicrograph of the transverse section the cells arc seen 
to be of nearly one size throughout the entire layer, being only slightly 
compressed in the fifth to the tenth row of cells of the latest growth 
in each ring. The walls of the tracheids are of nearly uniform thick- 
ness throughout the ring. In this wood there are no resin-ducts; 
there are, however, special resin-cells represeuted by a few black rect- 
angular spots, near the outer portion of each ring. This feature is com- 
mon to all the cedars I have examined, and also to the Sequoias. The 
diameter of the tracheids is the smallest of any of the Conifers under 
consideration, being only 0.0013 to 0.0015 of an inch, the lumen rang- 
ing from 0.0011 to 0.0013 of an inch. The medullary rays are very del- 
icate, and in this view hardly show a trace of an opening. 
The radial section was taken from a specimen of narrower layers than 
those of the transverse section. The longitudinally arranged cells of the 
tree are represented horizontally on the page. The lenticular markings 
are very small and close together, especially near the ends of the cells. 
The chain-like appearance of the small resin-cells shows for a short 
distance in the lower annual layer. The cells of the medullary rays, 
which are not abundant, run down the page, and, being very small aud 
generally tilled with resinous products, are not easily affected by fungi. 
The great delicacy of the medullary system is seen in the tangential 
section ; it is found to be composed of only siugle rows of cells, which 
are superimposed one above the other. Often but a single cell is found, 
yet bundles of two, three, or four cells are very common ; those of six- 
are interspersed at great intervals in this section, and now and then a 
larger bundle occurs. I have found the medullary system to be very 
delicate in all the cedars, which, in addition to the presence often of 
resinous matter, perhaps in a measure accounts for the slow lateral 
spread of the spots of decay in this wood. 
The impression made on one who for the first time sees ties of this 
wood, now being received by the railroad companies, would not be as 
favorable as that in the case of those who have bad a large experi- 
ence in their use. Out of many thousands which I saw just received by 
railroad companies this spring, not 10 per cent, were perfectly sound : 
yet, when put in the ground, they will last from eight to ten years. 
Some ties would have a decayed center, whileothers would have only 
five to ten small spots j but as long as there was sufficient room for 
spiking the ties were considered good, as they decay in the ground so 
slowly that their mechauical destruction under the traffic is accom- 
plished before they are completely rotted. 
From its great durability this wood is well adapted for railroads of 
moderate passenger and freight traffic. The ties with a 7- to 8 inch face, 
7 inches thick and S feet long, have this spring cost from 30 to 35 cents, 
while Chestnut ties of the same size cost 55 to G5 cents in the vicinity of 
* See Table II., Specific Gravity, p. 53. 
