THE YOUNG SCIENTIST. 
95 
centres, 11 inches, and swin<>-s 4 inches ; rests, 4 
and 8 inelies. It lias a solid emery wheel for 
^riudin^- and polishing- tools, metals, etc. The 
head has a spindle of steel, nicely litted, with 
face plate, spur centre, etc. The tail stock has 
a screw spindle of steel, with wheel, etc. It is fas- 
tened to the saw frame with the ball and socket 
joint, the same as used for the tilting-table. 
The saw and lathe are sold separate. 
#iu- look ^ibiiljlc. 
The Empire City Philatelist. A. M. Crouter, 
Editor and Publifsher, 155 West Broadway, New 
York. Piibhsiied monthly ; 50 cents per year. 
This publication is devoted to the interests of 
stamp and coin collectors. To those of our read- 
ers who are making collections of eitlier stamps 
■or coins, this journal would prove of great inter- 
est, as it describes the various stamps as they are 
issued, and contains considerable go.^sip regard- 
ing collections and collectors, sales of stamps, 
coins, and medals, and newsy chats of doings in 
the post-office department. Each number also 
contains contributions and correspondence from 
foreign countries concerning post-offlces, pos- 
tage-stamps, and old coins. The journal has 
many other pleasing features, and on the whole 
is a paper that will well repay its cost to all who 
are interested in the collection of postage-stamils, 
numismatics or coin collecting. 
Scientific Itcfos. 
— It has been popularly supposed that the 
rings of a tree furnished a reliable record of its 
age ill years. But Dr. A. L. Child writes t3 the 
Topular Science Monthly that this idea is errone- 
ous. His experiments go to show that the forma- 
tion and thickness of the rings depend upon the 
<'lianges in the atmosphere, and the more fre- 
quent these changes the greater the number of 
rings. Trees which he knew to be only twelve 
years old proved, upon being cut, to have thirty- 
five to forty rings. 
— On the authority of Mr. Woodbury, of Boston, 
it is stated that 40-light Brush dynamos in use at 
Adams, Mass.. require 36 and a fraction horse- 
power eacli. The cost of running arc lights in 
various steam mills, running, when lighted, 400 
hours per yeiw, is estimated by him at Gia cents 
per hour, of which i^i cents are for carbon, and 5 
cents for coal, attendance, depreciation and in- 
terest. When a mill runs nights the hourly cost 
is considoi'ably diminished. Where arc lights 
a,re substituted for kerosene lamps the ratio be- 
tween the two v:as, in one case mentioned, one 
arc light for eiglit kerosene lamps. These facts 
are of groat importance to manufacturers. 
~ A late report of a patent(Ml method of making 
artificial wood comes from Germany, where Herr 
B. Harrass has invented and put into pra,ctical 
operation a process which consists of the manip- 
ulation of a mass consisting chiefly of cellulose 
and starch. Common cellulose, sold in the form 
of paper, is reduced to pulp in water. To this is 
added, after being drained through a sieve, tliree 
parts by weight of starch and two parts by weight 
of wheat or maize meal. The compound, thor- 
oughly mixed, is put into tubes of thin metal 
and boiled over a water bath. When done the 
allotted time, and turned out after cooling, the 
mass resembles glue, which is then mixed with 
the same quantity of sawdust. This mass is 
rolled and left to dry in a hot room, and is then 
ready for use. For pressing into the desired 
shape iron or steel moulds are used, heated to 120 
degrees, and the mass is subjected to enormous 
pressure. After cooling, the article is said to re- 
semble wood, and can be treated in every respect 
as such, becoming with age bone-hard. It can be 
worked with the saw or file, can be colored, pol- 
ished, and, when desired, covered wdth veneer. 
— The cultivation of the singular parasitic 
shrub mistletoe for ornamental purposes is 
recommended in foreign papers, and young 
trees with mistletoe growing on them are offered 
for sale in English nurseries. It is generally 
found on the branches of apple-trees, but is not 
very particular in this respect, and takes its habi- 
tation also on different other trees. It may be 
raised from seed placed in the crevices of th(i 
bark of young, healthy branches; or it may be 
propagated by grafting, in which case, a piece 
with a portion of the bark of the tree from Avhich 
it is taken has to be cut with it, and firmly se- 
cured to the new position. The European species 
is larger and rather more ornamental than our 
native kind, for which reason the latter might 
not prove a success for exclusively ornamental 
purposes ; but if some enterprising florist should 
succeed in raising mistletoe in neat hanging- 
baskets, which might be hung ingeniously over 
doors and archways under which young people 
of both sexes have to pass— and older ones, too. 
for that matter— there might spring up quite a 
demand for the " novelty " about Christmas- 
time. 
Iprarfitiil |)ints 
Holes in Glass. —It is ^anid that a round hole 
of any desired size may be cut in a pane of glass 
without injury 1o tin- i>->ne by taking a copper 
tube of the size of the hoi - reouired and eq using 
it to revolve in contact with the glass, keeping 
the surface where the cut is to be made well sup- 
plied with emery and water. Of course, care 
must be taken to hold the glass firmly down and 
to prevfuit the tube from moving away from the 
spot where the hole is to be cut. 
