How can hydrogen be produced?

Mix one part of sulphuric acid with about five or six parts of water, always pouring the acid into the water, rather than the water into the acid, as there is danger of its flying into a person's face, if wrongly handled. Into this mixture put scraps of zinc. The chemical action between these two substances very soon produces the hydrogen gas. In using this gas, provision should always be made for expansion. Otherwise the gas is dangerous, and liable to burst the vessel containing it. It is a gas that should be handled with great care at all times.

How should a gas meter be read?

From the dials always take the figures the index hands have passed. Assuming on the high dial the hand is between 3 and 4, on the second dial, between 4 and 5, on the third dial, between 8 and 9, you would read 348; adding two cyphers for the hundreds, it would read 34,800. To ascertain the amount of gas consumed in a given time, deduct the previous register (as given on the gas bill), from the present register.

Why are wooden sinks and wash trays prohibited in most cities?

They are considered unsanitary, as they soon commence to decay and absorb the water. If water is not kept in them constantly, they are liable to shrink and leak.

Why is a pipe that has been heated, more easily bent than when cold?

The heat expands the particles or molecules of which the metal is composed, and there being less density, they pass by each other more easily.

What is the danger in overheating a pipe?

Overheating expands the metal to such an extent that the particles either lose their strength or are consumed by the heat.

What is carbonic acid gas?

It is the gas most dangerous to health, it being most common, and should be guarded against by means of proper ventilation. It being one of the heavy gases, it naturally falls, and will be found in the lower strata of air in a room. For this reason the ventilation of public buildings and living rooms should be from the lower part of the room near the floor. By placing the ventilation near the floor, we not only assist in correcting this evil, but by drawing in the cold air from the lower section of the room, the heated air of the upper sections is forced to fall, to fill this space. Thus a proper circulation of air in the room is established. Years ago, when houses were heated from fireplaces, headaches were seldom known, which was largely due to this same manner of ventilation.

How does cold act upon sewage?

It causes the grease contained in the sewage to separate from the liquid portion. The grease being lighter than the water, naturally rises to the surface.

In what plumbing device is this principle put to use? In the grease trap.

How should a tank be made which is to hold acid?

A tank that is to hold acid continuously, should be made of lead, burned together, and not soldered, as in time the acid destroys the solder.

How many cubic inches does a gallon contain?

A gallon contains 231 cubic inches.

What is the weight of a gallon of water?

8.33 pounds.

What is the weight of a cubic foot of water? 62.5 pounds.

How many gallons of water are contained in one cubic foot?

7.5 gallons.

What are proper heights for setting plumbing fixtures?

Kitchen sink, 2 ft. 7 in.; wash trays, 2 ft. 8 or 9 in.; wash bowl slab, 2 ft. 6 1/2 in.