# September 1, 110 years ago: trigonometry, the dollar rate and sparklers

For the Day of Knowledge, we have prepared an "antique" post. Since our product, the geometric core, is closely connected with mathematics, and more precisely with its sections “Differential Geometry” and “Numerical Methods”, mathematical curiosities cause us a special thrill. The family archive of one of the employees of C3D Labs keeps a calendar of students “Comrade” for the years 1909-1910. There is a lot of curious about mathematics and not only what we want to share. School e-magazine and Wikipedia is dedicated.

"Comrade" was not an ordinary diary, as we know it. In one small book, together with the schedule and estimates, the Orthodox calendar, a dictionary of foreign words, exchange rates, tips for photographers, courtesy rules, Bengal lights recipes and a lot of useful information fit. The calendar was produced in St. Petersburg by the Otto Kirchner Publishing House. The picture is clickable. Our calendar belonged to 11-year-old high school student Kohl Minko, who lived in Odessa with his parents and older sisters. Kolya Minko with sisters Olga and Anna (Picture is clickable) Kohl studied so-so. But later he corrected himself: he graduated from the Physics and Mathematics Faculty of Odessa University and worked as a design engineer. The picture is clickable

# Maths

Mathematical sections are located in the calendar immediately after the genealogy of the Russian sovereigns, which indicates the importance of the exact sciences. First come the table of squares / cubes and the table of initial numbers. Behind them is the multiplication table. The picture is clickable Next arithmetic and algebra - from the rules of multiplication and signs of divisibility to progressions and logarithms. The picture is clickable The picture is clickable The formula of the side of a regular 15 square, inscribed in a circle, looks impressive. Not all freshmen can withdraw it. A colleague from ASCON, who teaches at the department of engineering graphics, says that with the hexagon students have difficulty. The picture is clickable. Trigonometry gives the familiar formulas of sines, cosines and tangents.

The image is clickable

. Analytical geometry completes the mathematical part of the calendar. The picture is clickable The picture is clickable The rest exact sciences are presented modestly. Physics and astronomy fall on one page, on chemistry - two. The picture is clickable. But how compact the periodic table looked at the beginning of the 20th century. The picture is clickable

# Accounting

Why should a high school student learn mathematics? To count money! The calendar has a real account book for accounting of income / expenditure. Debtors and own debts were entered into separate signs. Picture clickable Picture clickable

# Geography

But Tovarishch did not prepare its owner for the modest life of the accountant in the county town. On the contrary, he tuned to travel and discovery. States and their rulers, the most populated cities of the world, railways, rivers and bridges, travel measures (kilometers / versts / miles) and length measures (tops / inches / centimeters), time zones, degrees Celsius and Fahrenheit, exchange rates - all that the gymnasium student should have known so as not to get lost in distant countries.

In 1909, in Annam (part of present-day Vietnam), Tam-Thai ruled, Negus Menelik II was in charge of Abyssinia (despots, as the calendar notes), and Morena (Moreira) Penn was president of the Brazilian United States. The picture is clickable. For pound sterling they gave 9 rubles. 45 ¾ pennies, for a dollar - 1 rub. 94.3 kopecks The picture is clickable

The most populated city in the world was London with 6.55 million inhabitants. In Moscow, there were 1.04 million people, in Beijing - only 1 million.

Literacy statistics of the population, alas, are not in our favor: in Russia there are 16 literate and 3 students per 100 souls, in Germany - 98 and 18, in the USA - 92 and 23 respectively. The picture is clickable. A list of the most important discoveries and inventions of the 19th century: smallpox inoculation, loom, tunnel under the Thames, telephone, telegraph, X-rays. Between them, hypnotism started. The picture is clickable

# To applicants

To continue education at the disposal of high school students was a list of higher educational institutions of the Russian Empire and the conditions for admission. The picture is clickable. And here is an extract from the statute of military service on the benefits and delays. Picture clickable Picture clickable

# Mail, telegraph, telephone

At the beginning of the 20th century, telephone communication slowly penetrated into life. For telephone for personal and family use in St. Petersburg charged 49 rubles. 50 kopecks per year, in Moscow - 71 rubles. 10 kopecks Compare with the cost of training: the Mining Institute of Empress Catherine II (St. Petersburg) - 100 rubles. per year, the Imperial Moscow Technical School - 75 rubles. in year. The picture is clickable. But the main means of communication over long distances remained letters for a long time, so the postal rules are set out in the calendar in the most detail. The picture is clickable

# Photo lovers

Photographers, rate! The calendar contains recipes for six types of developers: pyrogallic soda, durable pyrogallic with potassium meta-2-sulfur sulphate, hydroquinone, metol, glycine, mixed eicogenic-hydroquinone. The picture is clickable

# health and beauty

Perhaps this is the most wonderful section of the calendar, if you look at it from 2018. Here we brought first aid, a first-aid kit, hygiene tips and instructions on measures to protect against cholera.

Vaseline, French turpentine, quinine, Hoffman drops, Danish king drops, castor oil, carbolic acid are recommended in the home first aid kit.

First aid for burns and cuts - raw egg whites to eliminate pain and speed wound healing.

A saturated solution of naphthalene in liquid petrolatum is shown as an otkomamar, which should be lubricated with the face, neck and hands every 2-3 hours. The picture is clickable "In no case do not wear narrow shoes and high heels." We support! The picture is clickable

# Sparklers

Well, at the end of the promised recipe. For white light: saltpeter 76 h, sulfur 22 ½ h, antimonium 1 h.
And you can also make green, red, yellow, purple, orange fire and rain. The picture is clickable