102 TEACHING SCIENCE IN SECONDARY SCHOOLS

ing the benefits of personally planning and constructing
apparatus, the contact with more finely finished equipment
offers certain advantages. First, it sets standards of workman-
ship; second, it creates a respect for accuracy; third, it presents
certain phenomena for which the more intricate apparatus is
indispensable; you cannot improvise an X-ray tube.
 Plan each year, or every alternate year, to secure one useful
piece of the more expensive physical apparatus. They are not
the foundation of your course, but, wisely selected, they are
ornaments to it. They increase interest and create a respect
for the science. They will stimulate your own enthusiasm, per-
haps, and they will impress your visitors. But they should come
last, not first.
 A List of Equipment
 The following list is neither the largest nor the smallest be-
ginning for a laboratory. It is quite modest as to money expense,
but with these things you could keep a class thoroughly busy.
The items marked with an are for demonstration purposes,
and one article is usually sufficient. Other items are for students'
experiments; and, as a rule, there should be one article for each
two students. By proper assignment of problems in the labora-
tory, however, one piece of apparatus will serve several pairs
of students in succession.
 Tools and Measurements
 Improvise
 Liter block Stands of all kinds
 Secure Locally
 Files, round and triangular Glass cutter
 Glue pot and brush Metal saw
 Metal shears Pencil compasses
 Pliers and shears Plumb bobs
 Screw hooks and eyes Soldering set
 Thumb tacks Woodworking tools
 Purchase from Supply House
 Cross-section paper Double calipers
 Metal sticks Metric rules, 12-inch
 Protractors, cardboard 'Vernier caliper