In the holes drilled in a wooden tube in the concrete wall, there is always a lot of sand and dust. To remove them will help plastic or metal tube by simply inserting it into the hole and how to blow into it (but mind your eyes!).
S. DOROFEEV, p. vokhtoga, Vologda region.
Recommend to read
ASSISTANTS MOTORIST
DEVICE FOR CHARGING BATTERIES is a rectifier device with electronic current regulator (Fig. 1). A rectifier manufactured by bridge circuit of diodes V1 — V4 (Fig. 2), and the electronic...
MICROMACHINERY
The sled with the motor for the little ones. Before to introduce the following proposed material, I want to remind small note in No. 2 of our journal in 1979 — "Folding sled". Because...
